Fault diagnosis for mine hoist bearing based on EMD method

According to characteristics that frequency of vibration signals of hoist gear box bearing in coal mine changes all the time under varying load and speed conditions, EMD method was adopted for fault diagnosis for hoist bearing. In phase of larger drag force and greater rotating frequency, working status of bearing is adjusted according to energy ratio and root mean square energy of IMF components of bearing vibration signal under normal status and fault status, and fault position is determined by extracting marginal spectrum of fault signal frequency. The experimental results show EMD method can detect bearing fault of hoist gear box effectively

Visualizing the effect of phenyl group on the intra-or intermolecular vibrational dynamics of nitromethane, nitrobenzene and their mixtures by coherent anti-Stokes Raman scattering

We experimentally investigate the vibrational dynamics of nitromethane (NM), nitrobenzene (NB) and their mixtures using femtosecond time-resolved coherence anti-Stokes Raman scattering (CARS) spectroscopy. At first, we coherently excite Raman active modes of NM, NB and the beats arising from vibrational coupling can be clearly identified in CARS spectra. Results indicate that pairs of vibrational modes involved in the coupling correspond to different groups in one molecule. In a second stage, CARS spectroscopy is performed when vibrational modes of mixtures are collectively excited. NM/acetone and NM/methanol mixtures beats are not observed because the hydrogen bonds lead to a faster decoherence. On the other hand, evidences of beats and vibrational dephasing are found in NB/acetone and NB/methanol mixtures despite the fact that interactions in the mixture involve strong hydrogen bonds. The main reason behind this behavior is that phenyl group has a crucial influence on vibrational dynamics in mixtures. In particular, our results confirm that phenyl group bending mode at 425 cm−1 of NB is coupled with the other modes, and suggest may be instrumental in the energy transfer among molecules

Upregulation of GPR34 expression affects the progression and prognosis of human gastric adenocarcinoma by PI3K/PDK1/AKT pathway

Purpose. G-protein coupled receptor 34 (GPR34), which belongs to the G-protein coupled receptors superfamily, is reportedly expressed highly in the spread of several solid tumors. However, its expression in gastric primary tumor and potential role in gastric cancer development and progression have not been determined. Methods. Immunohistochemistry, realtime RT-PCR and western blot methods were used to determine GPR34 expression in human gastric cancer tissues/cell lines and matched adjacent tissues/ normal mucosal cell line. A statistical analysis was performed to establish the potential correlation between GPR34 expression and the patients’ clinicopathological characteristics, tumor progression, and prognosis. Stably transfected NCI-N87 cell lines with either GPR34 overexpression or knock-down were constructed to determine the effect of GPR34 on gastric cancer cell invasion and migration, and to explain the preliminary molecular mechanism of GPR34 in gastric cancer metastasis. Results. GPR34 is up-regulated in primary gastric cancer tissues/cell lines compared with matched adjacent tissues/normal mucosal cell line, and when the relationship between GPR34 expression and the the clinicopathological characteristics was analyzed, it was shown that GPR34 expression is significantly correlated with tumor differentiation, infiltration depth, and lymph node status and had a significant influence on prognosis. Furthermore, GPR34-overexpression increased while GPR34-knockdown inhibited NCI-N87 cell invasion in vitro by PI3K/PDK1/AKT pathway. Conclusions. Taken together, up-regulation of GPR34 expression in human gastric carcinoma may play a critical role in tumor progression and in determining patient prognosis. GPR34 may be a useful diagnostic or prognostic molecular biomarker, and a potential target for therapeutic intervention

Simultaneous Determination of Oleanolic Acid and Ursolic Acid by in Vivo Microdialysis via UHPLC-MS/MS Using Magnetic Dispersive Solid Phase Extraction Coupling with Microwave-Assisted Derivatization and Its Application to a Pharmacokinetic Study of <i>Arctiumlappa</i> L. Root Extract in Rats

Simultaneous detection of oleanolic acid and ursolic acid in rat blood by in vivo microdialysis can provide important pharmacokinetics information. Microwave-assisted derivatization coupled with magnetic dispersive solid phase extraction was established for the determination of oleanolic acid and ursolic acid by liquid chromatography tandem mass spectrometry. 2′-Carbonyl-piperazine rhodamine B was first designed and synthesized as the derivatization reagent, which was easily adsorbed onto the surface of Fe₃O₄/graphene oxide. Simultaneous derivatization and extraction of oleanolic acid and ursolic acid were performed on Fe₃O₄/graphene oxide. The permanent positive charge of the derivatization reagent significantly improved the ionization efficiencies. The limits of detection were 0.025 and 0.020 ng/mL for oleanolic acid and ursolic acid, respectively. The validated method was shown to be promising for sensitive, accurate, and simultaneous determination of oleanolic acid and ursolic acid. It was used for their pharmacokinetics study in rat blood after oral administration of <i>Arctiumlappa</i> L. root extract

Electric-field control of tri-state phase transformation with a selective dual-ion switch

Materials can be transformed from one crystalline phase to another by using an electric field to control ion transfer, in a process that can be harnessed in applications such as batteries1, smart windows2 and fuel cells3. Increasing the number of transferrable ion species and of accessible crystalline phases could in principle greatly enrich material functionality. However, studies have so far focused mainly on the evolution and control of single ionic species (for example, oxygen, hydrogen or lithium ions4, 5, 6, 7, 8, 9, 10). Here we describe the reversible and non-volatile electric-field control of dual-ion (oxygen and hydrogen) phase transformations, with associated electrochromic2 and magnetoelectric11 effects. We show that controlling the insertion and extraction of oxygen and hydrogen ions independently of each other can direct reversible phase transformations among three different material phases: the perovskite SrCoO3−δ (ref. 12), the brownmillerite SrCoO2.5 (ref. 13), and a hitherto-unexplored phase, HSrCoO2.5. By analysing the distinct optical absorption properties of these phases, we demonstrate selective manipulation of spectral transparency in the visible-light and infrared regions, revealing a dual-band electrochromic effect that could see application in smart windows2, 9. Moreover, the starkly different magnetic and electric properties of the three phases—HSrCoO2.5 is a weakly ferromagnetic insulator, SrCoO3−δ is a ferromagnetic metal12, and SrCoO2.5 is an antiferromagnetic insulator13—enable an unusual form of magnetoelectric coupling, allowing electric-field control of three different magnetic ground states. These findings open up opportunities for the electric-field control of multistate phase transformations with rich functionalities

Electric-field control of tri-state phase transformation with a selective dual-ion switch.

Materials can be transformed from one crystalline phase to another by using an electric field to control ion transfer, in a process that can be harnessed in applications such as batteries, smart windows and fuel cells. Increasing the number of transferrable ion species and of accessible crystalline phases could in principle greatly enrich material functionality. However, studies have so far focused mainly on the evolution and control of single ionic species (for example, oxygen, hydrogen or lithium ions). Here we describe the reversible and non-volatile electric-field control of dual-ion (oxygen and hydrogen) phase transformations, with associated electrochromic and magnetoelectric effects. We show that controlling the insertion and extraction of oxygen and hydrogen ions independently of each other can direct reversible phase transformations among three different material phases: the perovskite SrCoO3-δ (ref. 12), the brownmillerite SrCoO2.5 (ref. 13), and a hitherto-unexplored phase, HSrCoO2.5. By analysing the distinct optical absorption properties of these phases, we demonstrate selective manipulation of spectral transparency in the visible-light and infrared regions, revealing a dual-band electrochromic effect that could see application in smart windows. Moreover, the starkly different magnetic and electric properties of the three phases-HSrCoO2.5 is a weakly ferromagnetic insulator, SrCoO3-δ is a ferromagnetic metal, and SrCoO2.5 is an antiferromagnetic insulator-enable an unusual form of magnetoelectric coupling, allowing electric-field control of three different magnetic ground states. These findings open up opportunities for the electric-field control of multistate phase transformations with rich functionalities