System-level modelling and validation of a strain energy harvesting system by directly coupling finite element and electrical circuits

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.— There is a lack of system-level finite element (FE) model which can directly predict the performance of a piezoelectric energy harvester connected with interface circuits and electric load. This work developed a system-level model of piezoelectric strain energy harvesting system by directly coupling the finite element and electrical circuits. The strain energy harvester (SEH) is a macro fibber composite adhesively bonded to a composite beam. Simulations were performed with the SEH connected with three circuits individually (i) a load resistor, (ii) a rectifier terminated with a load resistor and (iii) a rectifier terminated with a smoothing capacitor and a load resistor. Experimental tests were carried out to validate the simulation results. Good agreements were observed between the simulated and measured results. The developed model is able to predict the performance of the energy harvesting system when different circuit was connected. The validated system-level model can be used for the design and optimization of piezoelectric energy harvesting system by investigating the interactions between energy harvester and electrical circuits

High affinity binding of H3K14ac through collaboration of bromodomains 2, 4 and 5 is critical for the molecular and tumor suppressor functions of PBRM1.

Polybromo-1 (PBRM1) is an important tumor suppressor in kidney cancer. It contains six tandem bromodomains (BDs), which are specialized structures that recognize acetyl-lysine residues. While BD2 has been found to bind acetylated histone H3 lysine 14 (H3K14ac), it is not known whether other BDs collaborate with BD2 to generate strong binding to H3K14ac, and the importance of H3K14ac recognition for the molecular and tumor suppressor function of PBRM1 is also unknown. We discovered that full-length PBRM1, but not its individual BDs, strongly binds H3K14ac. BDs 2, 4, and 5 were found to collaborate to facilitate strong binding to H3K14ac. Quantitative measurement of the interactions between purified BD proteins and H3K14ac or nonacetylated peptides confirmed the tight and specific association of the former. Interestingly, while the structural integrity of BD4 was found to be required for H3K14ac recognition, the conserved acetyl-lysine binding site of BD4 was not. Furthermore, simultaneous point mutations in BDs 2, 4, and 5 prevented recognition of H3K14ac, altered promoter binding and gene expression, and caused PBRM1 to relocalize to the cytoplasm. In contrast, tumor-derived point mutations in BD2 alone lowered PBRM1\u27s affinity to H3K14ac and also disrupted promoter binding and gene expression without altering cellular localization. Finally, overexpression of PBRM1 variants containing point mutations in BDs 2, 4, and 5 or BD2 alone failed to suppress tumor growth in a xenograft model. Taken together, our study demonstrates that BDs 2, 4, and 5 of PBRM1 collaborate to generate high affinity to H3K14ac and tether PBRM1 to chromatin. Mutations in BD2 alone weaken these interactions, and this is sufficient to abolish its molecular and tumor suppressor functions

Vehicle emission and atmospheric pollution in China: problems, progress, and prospects

China has been the largest vehicle market in the world since 2009. The stalemate between the rapid development of the vehicle industry and delayed vehicle emission control has become increasingly prominent. Vehicle emission has become a significant source of air pollution in China’s cities. Understanding the current barriers in the vehicle industry is necessary for the development of effective and sustainable measures and policy to manage vehicle-induced air pollution. This review provides insight into the circumstances and causes of vehicle-induced air pollution and outlines recent progress in policy-makers’ long-term strategies and regulations. The development of an integrated mechanism of social participation, technical revolution, and regulatory innovation in vehicles, fuel, and roads is suggested to break the stalemate between air pollution and the automobile boom in China; the implications of this review extend to other countries facing the similar atmospheric pollution problems

Pendulum energy harvester with torsion spring mechanical energy storage regulator

This paper presents the integration of a novel mechanical torsion spring regulator into a pendulum energy harvester system. This regulator was designed to provide the same voltage-smoothing benefits of a flywheel without the start-up issues caused by increasing system inertia. In addition, the introduction of the spring between the input and output stages of the device acts as a buffer for any sudden impacts, which not only allows the energy from such events to be fully absorbed and dissipated slowly through the output but significantly reduces the torque stress and torque fluctuation stress on critical components to improve the reliability of the system. Through experimentation and simulation, the transducer was shown to reduce the voltage fluctuation range from 13.85 to 28.16 V to 16.41 to 23.59 V for the pendulum energy harvester at resonance, and comparison of start-up response to that of a device with a flywheel shows a significant improvement in initial acceleration of the output when subjected to excitation. The energy harvester with spring has demonstrated a maximum normalised average power output of 12.09 W/g2, a maximum normalised average voltage of 109.96 V/g, and a maximum normalised power density of 7.8 W/g2/kg, at a resonant frequency of 1.2 Hz. The effectiveness of the spring mechanism for regulating output voltage and power, improving start-up performance, and reducing stress on critical components has significant implications for the real-world viability of pendulum energy harvesters, with the potential to improve their reliability in often unpredictable environments.</p

Writing in London. Home and Languaging in the Work of London Poets of Chinese Descent

This essay discusses literary works produced in London by poets of Chinese descent who are foreign-born or London native. Some of these works are written in English, and some in Chinese. The aim is to discuss poetry that has emphatically or reluctantly embraced the identity narrative, talking of home and belonging in substantially different ways from each other, according to each poet’s individual relationship with movement, migration, and stability. Therefore, through the use of the phrase ‘London poets of Chinese descent’, I do not aim at tracing a shared sense of identity, but instead I am interested in using London as a method for an oblique reading that recognises the variety of angles and approaches in these poets’ individual experience, history and circumstances that can range from occasional travel to political exile

The Nonsubsampled Contourlet Transform Based Statistical Medical Image Fusion Using Generalized Gaussian Density

We propose a novel medical image fusion scheme based on the statistical dependencies between coefficients in the nonsubsampled contourlet transform (NSCT) domain, in which the probability density function of the NSCT coefficients is concisely fitted using generalized Gaussian density (GGD), as well as the similarity measurement of two subbands is accurately computed by Jensen-Shannon divergence of two GGDs. To preserve more useful information from source images, the new fusion rules are developed to combine the subbands with the varied frequencies. That is, the low frequency subbands are fused by utilizing two activity measures based on the regional standard deviation and Shannon entropy and the high frequency subbands are merged together via weight maps which are determined by the saliency values of pixels. The experimental results demonstrate that the proposed method significantly outperforms the conventional NSCT based medical image fusion approaches in both visual perception and evaluation indices

Fairness in Face Presentation Attack Detection

Face presentation attack detection (PAD) is critical to secure face recognition (FR) applications from presentation attacks. FR performance has been shown to be unfair to certain demographic and non-demographic groups. However, the fairness of face PAD is an understudied issue, mainly due to the lack of appropriately annotated data. To address this issue, this work first presents a Combined Attribute Annotated PAD Dataset (CAAD-PAD) by combining several well-known PAD datasets where we provide seven human-annotated attribute labels. This work then comprehensively analyses the fairness of a set of face PADs and its relation to the nature of training data and the Operational Decision Threshold Assignment (ODTA) on different data groups by studying four face PAD approaches on our CAAD-PAD. To simultaneously represent both the PAD fairness and the absolute PAD performance, we introduce a novel metric, namely the Accuracy Balanced Fairness (ABF). Extensive experiments on CAAD-PAD show that the training data and ODTA induce unfairness on gender, occlusion, and other attribute groups. Based on these analyses, we propose a data augmentation method, FairSWAP, which aims to disrupt the identity/semantic information and guide models to mine attack cues rather than attribute-related information. Detailed experimental results demonstrate that FairSWAP generally enhances both the PAD performance and the fairness of face PAD

The temporal changes of pigments content and key enzyme activities during autumnal turning period of Pistacia chinensis bunge

In this study, the temporal regularity of pigments and key enzyme intermediates of Pistacia chinensis Bunge in the color-changing period was investigated to provide a theoretical basis for exploring the mechanism of leaf discoloration. The pigment content and activities of key enzymes of P. chinensis during leaf discoloration were investigated. The correlation between leaf discoloration and environmental factors (temperature, relative humidity, light) was also analyzed. During the color change, the chlorophyll content decreased, while no significant change in the carotenoid content was observed. The anthocyanin content significantly increased in the middle of the period of color change. The ratios of carotenoids/chlorophyll and anthocyanins/chlorophyll showed an upward trend during the period of color change. The lightness parameter (L) and hue parameter (B) of P. chinensis Bunge leaves showed a fluctuating tendency, reaching the highest value at the beginning of color conversion. The hue parameter (A) showed an upward trend at the color conversion stage. The 5-aminolevulinic acid (ALA) and porphobilinogen (PBG) values showed an upward-downward-upward trend. The contents of ALA and PBG at the end of the color transformation were 2.01 times and 2.88 times higher than those at the beginning. The activity of phenylalaninammo-nialyase increased during the color change period. Chalcone isomerase and chalcone synthase first increased, then declined, reaching their highest level in the middle of color conversion, 261.0 u/g and 157.3 u/g, respectively. Although the activities of both enzymes declined at the end of the color conversion, they were higher than at the beginning of the color change. Anthocyanin content was negatively correlated with temperature, relative humidity, day length, and chalcone isomerase, whereas it was positively correlated with phenylalaninammo-nialyase. The results revealed the reasons for the discoloration of P. chinensis leaves in autumn and thus should be considered when exploring the mechanism of color-changing plants and performing color-changing plant applications

Wielding the sword: President Xi’s new anti-corruption campaign

A state achieves legitimacy through multiple sources, one of which is the effectiveness of its governance. Generations of scholars since Hobbes have identified the maintenance of peace and order as core functions of a legitimate state. In the modern world, economic prosperity, social stability and effective control of corruption often provide adequate compensation for a deficit of democracy. Corruption closely correlates with legitimacy. While a perceived pervasive, endemic corruption undermines the legitimacy of a regime, a successful anti-corruption campaign can allow a regime to recover from a crisis of legitimacy (Gilley 2009; Seligson and Booth 2009). This is the rationale behind the periodical campaigns against corruption that have been conducted by the Chinese Communist Party (‘Party’ or ‘CCP’) (Manion 2004; Wedeman 2012). Political leaders in China have found it expedient to use anti-corruption campaigns to remove their political foes, to rein in the bureaucracy and to restore public confidence in their ability to rule. Through anti-corruption campaigns, emerging political leaders consolidate their political power, secure loyalty from political factions and regional political forces, and enhance their legitimacy in the eyes of the general public. In an authoritarian state that experiences a high level of corruption, an anti-corruption campaign is a delicate political battle that addresses two significant concerns. The first concern is to orchestrate the campaign so that it is regime-reinforcing instead of regime-undermining. To remain credible, the regime must demonstrate its willingness and capacity to punish corrupt officials at the highest levels.preprin