Does enterprise risk management benefit manufacturing firms? Evidence from China

It is observed that Enterprise risk management (ERM) framework has been adopted by some manufacturing firms in China in the past years. To investigate the effectiveness of ERM, data of A-share listed manufacturing firms in Shanghai and Shenzhen stock exchange during 2010-2019 are adopted from Wind database and CSMAR database, two large domestic databases, to examine the impact of ERM on value of manufacturing firms. Treatment effects model and genenralised method of moments (GMM) are employed to derive the empirical results. Our results show that adoption of ERM can add value to the firms, and firms benefitmore from high-quality ERM program. Furthermore, the impact of ERM seems to be more significant among the manufacturing firms with smaller scale, or stronger institutional shareholding, or international business. Our findings encourage the manufacturing firms to implement ERM program and improve the program to achieve its targets

A General Unfolding Speech Enhancement Method Motivated by Taylor's Theorem

While deep neural networks have facilitated significant advancements in the field of speech enhancement, most existing methods are developed following either empirical or relatively blind criteria, lacking adequate guidelines in pipeline design. Inspired by Taylor's theorem, we propose a general unfolding framework for both single- and multi-channel speech enhancement tasks. Concretely, we formulate the complex spectrum recovery into the spectral magnitude mapping in the neighborhood space of the noisy mixture, in which an unknown sparse term is introduced and applied for phase modification in advance. Based on that, the mapping function is decomposed into the superimposition of the 0th-order and high-order polynomials in Taylor's series, where the former coarsely removes the interference in the magnitude domain and the latter progressively complements the remaining spectral detail in the complex spectrum domain. In addition, we study the relation between adjacent order terms and reveal that each high-order term can be recursively estimated with its lower-order term, and each high-order term is then proposed to evaluate using a surrogate function with trainable weights so that the whole system can be trained in an end-to-end manner. Given that the proposed framework is devised based on Taylor's theorem, it possesses improved internal flexibility. Extensive experiments are conducted on WSJ0-SI84, DNS-Challenge, Voicebank+Demand, spatialized Librispeech, and L3DAS22 multi-channel speech enhancement challenge datasets. Quantitative results show that the proposed approach yields competitive performance over existing top-performing approaches in terms of multiple objective metrics.Comment: Submitted to TASLP, revised version, 17 page

Application of evolution-based uncertainty design on gear

The evolution of mechanical parameters, a factor affecting the mechanical reliability, has gathered more attention nowadays. However, studies on time varying uncertainty can hardly be found. A new method based on evolution-based uncertainty design (EBUD) is applied to the design of gear in this paper. Considering the wear evolution over the lifetime, a tooth wear’s time-varying uncertainty model based on the continuous-time model and Ito lemma is established. Drift and volatility functions dependent on the drift rate and volatility rate of rotational speed and torque are used to express the time-varying uncertainty of tooth thickness. The method can predict the reliability and provide an instruction in reliability improving, maintenance and repair of the gear system

Middle-Late Jurassic magmatism in the west central Lhasa subterrane, Tibet: Petrology, zircon chronology, elemental and Sr-Nd-Pb-Hf-Mg isotopic geochemistry

Mesozoic magmatic rocks are widespread in the Lhasa terrane, but most of them are of cretaceous age. Because Jurassic rocks are relatively rare and our knowledge on such earlier magmatism in the context of the tectonic setting and evolution is limited. In this study, we focus on the mid-late Jurassic granitoids that occur in the west central Lhasa subterrane. We present the results of a systematic study of these granitoid rocks of tonalite composition together with the hosted mafic magmatic enclaves. We dated 4 representative tonalite samples and 2 enclaves using zircon U-Pb method that gives the age range of 167–154 Ma. All these samples have Sr-Nd-Pb isotopic compositions (87Sr/86Sr = 0.713941–0.718417, εNd(t) = −14 to −9.8, 206Pb/204Pb = 18.806–18.936, 207Pb/204Pb = 15.739–15.764, 208Pb/204Pb = 39.257–39.798) similar to the composition of gneisses from the basement of the Lhasa terrane, suggesting that magmas parental to these mid-late Jurassic granitoids of tonalitic composition are of largely crustal origin, which is also supported by the petrographic observations. Both of the tonalite samples and the mafic enclaves have a wide span of zircon εHf(t) of −15.9 to −0.2 and − 13.8 to −7.4, respectively. These samples also show varying δ26Mg ranging from −0.40 to −0.18, with an average δ26Mg = −0.27 ± 0.06‰ (2SD) that is best understood as representing the Mg composition of the continental crust of the Lhasa terrane. All these observations allow us to conclude that basaltic melts derived from metasomatized mantle were involved in the petrogenesis of these granitoids. Specifically, southward subduction of the Bangong-Nujiang Ocean lithosphere and subsequent slab rollback metasomatized the mantle wedge and the lithospheric mantle above, whose melting produced basaltic magmas. Underplating and intrusion of these basaltic magmas caused crustal melting and generation of granitoid magmas parental to the tonalite and enclaves we study

Unveiling the pollution and risk of atmospheric (gaseous and particulate) polycyclic aromatic hydrocarbons (PAHs) in a heavily polluted Chinese city: A multi-site observation research

Linfen, one of the most polluted cities in China, releases huge amounts of polycyclic aromatic hydrocarbons (PAHs) into the atmosphere. The pollution characteristics of Linfen's PAHs, along with their emission sources and health risks, were scarcely discussed. This study conducted a multi-site observation campaign in Linfen during the non-heating and heating periods (2018–2019) using passive air samplers. Sixteen PAHs were analyzed for the gaseous and particulate samples collected at the 15 sites in the urban, rural, and background areas. The PAH concentrations in Linfen's atmosphere were 225.7 ± 81.9 ng m−3 during the heating period and 139.9 ± 47.5 ng m−3 during the non-heating period, annually averaged to 168.1 ± 58.6 ng m−3, which was predominantly contributed by the rural and urban emissions. Combustion was highly responsible for the PAHs, including the burning of coal for industrial production and winter heating, coupled with the utilization of oils by automobile engines. The spatiotemporal variations of PAHs were associated with the discrepancy of emission intensity rather than that of emission type. The BaP equivalent concentrations for the rural and urban areas were 1-2 orders of magnitude higher than the various international standards, indicating the considerable carcinogenic risk for the majority of local residents. These findings are informative for better understanding the atmospheric PAH pollution in a typical resource-based Chinese city.This study was supported by the National Natural Science Foundation of China (41001344, 42205099), the Priority Academic Program Development of Jiangsu Higher Education Institutions (164320H116), the Special Science and Technology Innovation Program for Carbon Peak and Carbon Neutralization of Jiangsu Province (BE2022612), and the Postdoctoral Research Foundation of China (2021M700792, 2023T160111).Peer reviewe

Syntaxin of plants71 plays essential roles in plant development and stress response via regulating pH homeostasis

SYP71, a plant-specific Qc-SNARE with multiple subcellular localization, is essential for symbiotic nitrogen fixation in nodules in Lotus, and is implicated in plant resistance to pathogenesis in rice, wheat and soybean. Arabidopsis SYP71 is proposed to participate in multiple membrane fusion steps during secretion. To date, the molecular mechanism underlying SYP71 regulation on plant development remains elusive. In this study, we clarified that AtSYP71 is essential for plant development and stress response, using techniques of cell biology, molecular biology, biochemistry, genetics, and transcriptomics. AtSYP71-knockout mutant atsyp71-1 was lethal at early development stage due to the failure of root elongation and albinism of the leaves. AtSYP71-knockdown mutants, atsyp71-2 and atsyp71-3, had short roots, delayed early development, and altered stress response. The cell wall structure and components changed significantly in atsyp71-2 due to disrupted cell wall biosynthesis and dynamics. Reactive oxygen species homeostasis and pH homeostasis were also collapsed in atsyp71-2. All these defects were likely resulted from blocked secretion pathway in the mutants. Strikingly, change of pH value significantly affected ROS homeostasis in atsyp71-2, suggesting interconnection between ROS and pH homeostasis. Furthermore, we identified AtSYP71 partners and propose that AtSYP71 forms distinct SNARE complexes to mediate multiple membrane fusion steps in secretory pathway. Our findings suggest that AtSYP71 plays an essential role in plant development and stress response via regulating pH homeostasis through secretory pathway

Study on Harmless Disposal Process of Beneficiation Tailings for a Gold Mine in Fujian Province

In order to promote the sustainable development of a gold mine in Fujian Province, based on the upstream beneficiation process and indicators, the treatment of beneficiation tailings (carbon leaching tail pulp and heap leaching residues) was studied in detail. The results showed that: Applying alkali-chlorination (bleaching powder) process in treatment for the cyanide containing waste liquid in carbon leaching tail pulp, the cyanide can be effectively removed, the CN- concentration is reduced from 250 mg/L to 0.217 mg/L, and the removal rate is more than 99.90%. The test index is successfully applied to the production practice, and the effect is also remarkable. The developed beneficiation tailings harmless disposal process, that is, solid slag muck (carbon leaching and heap leaching residues) mixed emissions for ecological restoration, carbon leaching wastewater after reaching the cyanide concentration standard is recycled or discharged according to the actual production, which greatly saves the storage capacity of tailings pond and reduces the occupation of waste dump. The production practice can provide basic basis for the end treatment of beneficiation tailings in the same type of gold mines