The Mechanism by Which Ionic Liquids Enable Shilov-Type CH Activation in an Oxidizing Medium

Quantum mechanical studies on methane CH activation catalyzed by PtCl_2 in concentrated H_2SO_4 and ionic liquid solution show that the effect of the ionic liquid is to enable Shilov-like chemistry in an oxidizing medium, by solvating the otherwise insoluble PtCl_2(s) in H_2SO_4. Other possible mechanisms have been investigated and discarded

Time-frequency analyses of blasting vibration signals in single-hole blasting model experiments

With common horseshoe cavern in underground engineering as the prototype, three single-hole blasting model experiments have been carried out. And coupled SPH-FEM approach is adopted for analyzing the limit effect of pre-excavated horseshoe cavern on blasting crater. During the experiment, the blasting vibration signals on the top surface of cemented sand model have been recorded. Then Hilbert-Huang transform has been applied to analyzing the time-frequency characteristics of recorded blasting vibration signals. Both experiment results and numerical cases indicate that the range of blasting crater is controlled effectively by pre-excavating horseshoe cavern, and the limit effect of pre-excavating on blasting crater has a close connection with its length. Moreover, the 50 mm pre-excavated horseshoe cavern presents an amplification effect in blasting vibration effect both along the blasthole direction and perpendicular to the blasthole direction, and it also demonstrates a weaken effect in the main blasting vibration frequency of vertical blasting vibration signal. HHT analyses of vertical blasting vibration signals show that single-hole blasting vibration signals present a centralized distribution in time domain and an uneven distribution in frequency domain. The dominant energy of blasting vibration signal is distributed in several IMF components, where main blasting vibration frequency locates. When cutting the charge, the blasting vibration effect will be reduced, while the main blasting vibration frequency of blasting vibration signal will be increased

DPSA: Dense pixelwise spatial attention network for hatching egg fertility detection

© 2020 SPIE and IS & T. Deep convolutional neural networks show a good prospect in the fertility detection and classification of specific pathogen-free hatching egg embryos in the production of avian influenza vaccine, and our previous work has mainly investigated three factors of networks to push performance: depth, width, and cardinality. However, an important problem that feeble embryos with weak blood vessels interfering with the classification of resilient fertile ones remains. Inspired by fine-grained classification, we introduce the attention mechanism into our model by proposing a dense pixelwise spatial attention module combined with the existing channel attention through depthwise separable convolutions to further enhance the network class-discriminative ability. In our fused attention module, depthwise convolutions are used for channel-specific features learning, and dilated convolutions with different sampling rates are adopted to capture spatial multiscale context and preserve rich detail, which can maintain high resolution and increase receptive fields simultaneously. The attention mask with strong semantic information generated by aggregating outputs of the spatial pyramid dilated convolution is broadcasted to low-level features via elementwise multiplications, serving as a feature selector to emphasize informative features and suppress less useful ones. A series of experiments conducted on our hatching egg dataset show that our attention network achieves a lower misjudgment rate on weak embryos and a more stable accuracy, which is up to 98.3% and 99.1% on 5-day and 9-day old eggs, respectively

Functional characterization of a short peptidoglycan recognition protein from Chinese giant salamander (Andrias davidianus)

This work was supported by the National Natural Science Foundation of China (Grant no. 31302221, 31172408 and 31272666) and Jiangsu Province (Grant no. BK20171274 and BK2011418), and partially by the Opening Project of Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland (Grant no. K2016-08). QZ was supported by the “Qinglan” project of Jiangsu province of China.Peer reviewedPublisher PD

Hard rock deep hole cutting blasting technology in vertical shaft freezing bedrock section construction

Using the traditional cutting blasting technology in vertical shaft construction has some features, e.g. slows driving speed, gangue with large volume and throwing high. Moreover, large explosive charge initiation has a serious influence on freezing pipes and freezing wall. In this study, the periphery hole charge and charge structure was optimized, and the blasting model of the bedrock vertical shaft section was established by using the ANSYS/LS-DYNA numerical simulation software. In addition, stress concentration of the large diameter empty hole and its influence of blasting efficiency in blasting were analyzed. The field experiment was conducted to verify the blasting results. The results show that using large diameter empty hole blasting technology in vertical shaft construction of frozen hard rock section can significantly improve the speed of vertical shaft construction, obtain the excellent blasting effect and guarantee the safety of freezing pipes and freezing wall

PKC-induced Sensitization of Ca2+-dependent Exocytosis Is Mediated by Reducing the Ca2+ Cooperativity in Pituitary Gonadotropes

The highly cooperative nature of Ca2+-dependent exocytosis is very important for the precise regulation of transmitter release. It is not known whether the number of binding sites on the Ca2+ sensor can be modulated or not. We have previously reported that protein kinase C (PKC) activation sensitizes the Ca2+ sensor for exocytosis in pituitary gonadotropes. To further unravel the underlying mechanism of how the Ca2+ sensor is modulated by protein phosphorylation, we have performed kinetic modeling of the exocytotic burst and investigated how the kinetic parameters of Ca2+-triggered fusion are affected by PKC activation. We propose that PKC sensitizes exocytosis by reducing the number of calcium binding sites on the Ca2+ sensor (from three to two) without significantly altering the Ca2+-binding kinetics. The reduction in the number of Ca2+-binding steps lowers the threshold for release and up-regulates release of fusion-competent vesicles distant from Ca2+ channels

IoT and Wearable Devices-Enhanced Information Provision of AR Glasses: A Multi-Modal Analysis in Aviation Industry

While Augmented Reality (AR) glasses are now instrumental in industries for delivering work-related information, the current one-size-fits-all information provision of AR glasses fails to cater to diverse workers’ needs and environmental conditions. We propose a framework for harnessing Internet of thing (IoT) and wearable technology to improve the adaptability and customization of information provision by AR. As a preliminary exploration, this short paper develops a multi-modal data processing system for work performance classification in the aviation industry. Using machine learning algorithms for multi-modal feature extraction and classifier construction, this framework provides a more objective and consistent evaluation of work performance compared to single-modal approaches. The proposed analytics architecture can provide valuable insights for other industries struggling to implement IoT and mixed reality