Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
9,175
result(s) for
"Qian, Jing"
Sort by:
Dynamic Modelling and Calculation of Crank Slider Mechanism of Multiparameter Friction Model in Wireless Communication
In this research work, an advanced wireless communication-based crank slider mechanism for multiparameter friction techniques is analyzed. The earlier models are unable to find exact friction; therefore, a correct crank function cannot be identified. The dynamic crank sliding mechanism is required for advanced mechanical applications. The available models are not suitable for future mechanical exhibiting. In this work, an SVM-based crank slider with a dynamic friction model is implemented. The SVM mathematical technique continually balances dynamic modeling with friction balancing. Finally, the controller/observer methods showed effective numerical outcomes. The variables of the system are analyzed, noting the mistakes and the estimations that are made. The performance measures accuracy of 98.45%, sensitivity of 97.34%, crank slider of 96.34%, and recall at 97.34%.
Journal Article
The impact of corporate digital transformation on the export product quality: Evidence from Chinese enterprises
The digital economy has become a driving force in the rapid development of the global economy and the promotion of export trade. Pivotal in its advent, the digital transformation of enterprises utilizes cloud computing, big data, artificial intelligence, and other digital technologies to provide an impetus for evolution and transformation in various industries and fields. in enhancing quality and efficiency. This has been critical for enhancing both quality and efficiency in enterprises based in the People’s Republic of China. Through the available data on its listed enterprises, this paper measures their digital transformation through a textual analysis and examines how this transformation influences their export product quality. We then explore the possible mechanisms at work in this influence from the perspective of enterprise heterogeneity. The results find that: (1) Digital transformation significantly enhances the export product quality in an enterprises, and the empirical findings still hold after a series of robustness tests; (2) Further mechanism analysis reveals that the digital transformation can positively affect export product quality through the two mechanisms of process productivity ( φ ), the ability to produce output using fewer variable inputs, and product productivity ( ξ ), the ability to produce quality with fewer fixed outlays; (3) In terms of enterprise heterogeneity, the impact of digital transformation on export product quality is significant for enterprises engaged in general trade or high-tech industries and those with strong corporate governance. In terms of heterogeneity in digital transformation of enterprise and the regional digital infrastructure level, the higher the level of digital transformation and regional digital infrastructure, the greater the impact of digital transformation on export product quality. This paper has practical implications for public policies that offer vital aid to enterprises as they seek digital transformation to remain sync with the digital economy, upgrade their product quality, and drive the sustainable, high-quality, and healthy development of their nation’s economy.
Journal Article
Improved Discharge Energy Density of Poly(vinylidene fluoride)-Based Nanocomposites via a Small Amount of Dopamine-Modified TiO2 Nanosheets
Dielectric capacitors have attracted increasing attention for their fast charge–discharge speeds as well as high power density, and they have been widely used in advanced electronics and electric power systems. Here, dopamine-modified TiO
2
(TiO
2
@PDA) nanosheets were synthesized via hydrothermal reaction and in situ polymerization. Then the synthesized TiO
2
@PDA nanosheets were introduced into the poly(vinylidene fluoride) (PVDF) matrix via solution blending. Our results reveal that loading a small amount of TiO
2
@PDA nanosheets can effectively enhance the energy storage performance of the nanocomposites. For example, a superior discharge energy density with 10.53 J/cm
3
is obtained for the 9 wt.% TiO
2
@PDA/PVDF nanocomposite at 195 MV/m, which is 1.75 times as large as discharge energy density of pure PVDF (6.01 J/cm
3
at 170 MV/m). Such significant improvement is due to the large aspect ratio as well as dopamine modification of the TiO
2
nanosheets. The study provides a feasible way to prepare the nanocomposites with excellent energy storage performance.
Journal Article
RNA modification: mechanisms and therapeutic targets
RNA modifications are dynamic and reversible chemical modifications on substrate RNA that are regulated by specific modifying enzymes. They play important roles in the regulation of many biological processes in various diseases, such as the development of cancer and other diseases. With the help of advanced sequencing technologies, the role of RNA modifications has caught increasing attention in human diseases in scientific research. In this review, we briefly summarized the basic mechanisms of several common RNA modifications, including m6A, m5C, m1A, m7G, Ψ, A-to-I editing and ac4C. Importantly, we discussed their potential functions in human diseases, including cancer, neurological disorders, cardiovascular diseases, metabolic diseases, genetic and developmental diseases, as well as immune disorders. Through the “writing-erasing-reading” mechanisms, RNA modifications regulate the stability, translation, and localization of pivotal disease-related mRNAs to manipulate disease development. Moreover, we also highlighted in this review all currently available RNA-modifier-targeting small molecular inhibitors or activators, most of which are designed against m6A-related enzymes, such as METTL3, FTO and ALKBH5. This review provides clues for potential clinical therapy as well as future study directions in the RNA modification field. More in-depth studies on RNA modifications, their roles in human diseases and further development of their inhibitors or activators are needed for a thorough understanding of epitranscriptomics as well as diagnosis, treatment, and prognosis of human diseases.
Journal Article
A Survey on Collaborative DNN Inference for Edge Intelligence
With the vigorous development of artificial intelligence (AI), intelligence applications based on deep neural networks (DNNs) have changed people’s lifestyles and production efficiency. However, the large amount of computation and data generated from the network edge becomes the major bottleneck, and the traditional cloud-based computing mode has been unable to meet the requirements of realtime processing tasks. To solve the above problems, by embedding AI model training and inference capabilities into the network edge, edge intelligence (EI) becomes a cutting-edge direction in the field of AI. Furthermore, collaborative DNN inference among the cloud, edge, and end devices provides a promising way to boost EI. Nevertheless, at present, EI oriented collaborative DNN inference is still in its early stage, lacking systematic classification and discussion of existing research efforts. Motivated by it, we have comprehensively investigated recent studies on EI-oriented collaborative DNN inference. In this paper, we first review the background and motivation of EI. Then, we classify four typical collaborative DNN inference paradigms for EI, and analyse their characteristics and key technologies. Finally, we summarize the current challenges of collaborative DNN inference, discuss future development trends and provide future research directions.
Journal Article
Study on the Anti-Mycobacterium marinum Activity of a Series of Marine-Derived 14-Membered Resorcylic Acid Lactone Derivatives
With the emergence of drug-resistant strains, the treatment of tuberculosis (TB) is becoming more difficult and there is an urgent need to find new anti-TB drugs. Mycobacterium marinum, as a model organism of Mycobacterium tuberculosis, can be used for the rapid and efficient screening of bioactive compounds. The 14-membered resorcylic acid lactones (RALs) have a wide range of bioactivities such as antibacterial, antifouling and antimalarial activity. In order to further study their bioactivities, we initially constructed a 14-membered RALs library, which contains 16 new derivatives. The anti-M. marinum activity was evaluated in vitro. Derivatives 12, 19, 20 and 22 exhibited promising activity with MIC90 values of 80, 90, 80 and 80 μM, respectively. The preliminary structure–activity relationships showed that the presence of a chlorine atom at C-5 was a key factor to improve activity. Further studies showed that 12 markedly inhibited the survival of M. marinum and significantly reduced the dosage of positive drugs isoniazid and rifampicin when combined with them. These results suggest that 12 is a bioactive compound capable of enhancing the potency of existing positive drugs, and its effective properties make it a very useful leads for future drug development in combating TB resistance.
Journal Article
Azimuthal modulation of electromagnetically induced grating using structured light
We propose a theoretical scheme for creating a two-dimensional Electromagnetically Induced Grating in a three-level
Λ
-type atomic system interacting with a weak probe field and two simultaneous position-dependent coupling fields—a two dimensional standing wave and an optical vortex beam. Upon derivation of the Maxwell wave equation, describing the dynamic response of the probe light in the atomic medium, we perform numerical calculations of the amplitude, phase modulations and Fraunhofer diffraction pattern of the probe field under different system parameters. We show that due to the azimuthal modulation of the Laguerre–Gaussian field, a two-dimensional asymmetric grating is observed, giving an increase of the zeroth and high orders of diffraction, thus transferring the probe energy to the high orders of direction. The asymmetry is especially seen in the case of combining a resonant probe with an off-resonant standing wave coupling and optical vortex fields. Unlike in previously reported asymmetric diffraction gratings for PT symmetric structures, the parity time symmetric structure is not necessary for the asymmetric diffraction grating presented here. The asymmetry is due to the constructive and destructive interference between the amplitude and phase modulations of the grating system, resulting in complete blocking of the diffracted photons at negative or positive angles, due to the coupling of the vortex beam. A detailed analysis of the probe field energy transfer to different orders of diffraction in the case of off-resonant standing wave coupling field proves the possibility of direct control over the performance of the grating.
Journal Article
Comparative analysis of flood characteristic changes under Meiyu and typhoon rainfall in Zhejiang Province, China (1964–2021)
Climate change exerts heterogeneous impacts on regional flood extremes. This study focuses on the XF watershed (dominated by Meiyu) and HJT watershed (dominated by typhoons) in Zhejiang Province from 1964 to 2021. The Annual Maximum Flood (AMF) method and Peaks-Over-Threshold (POT) method were employed to analyze the differences in extreme flood characteristics before and after 1990. The results indicate that the Meiyu-dominated XF watershed shows stability: the 100-year design flood decreased by 2.3% using the AMF method and increased by 3.9% using the POT method. In contrast, the typhoon-dominated HJT watershed exhibits a decoupled response of “decreased frequency - amplified intensity”: the annual exceedance rate decreased from 1.885 to 1.808 events per year (a 4.1% reduction), while the Generalized Pareto Distribution (GPD) scale parameter increased by 42.2%. There is a significant discrepancy in the estimated values between the two methods in the HJT watershed (AMF: +64.2%; POT: +7.0%), highlighting the vulnerability of the AMF method in highly variable systems. This study reveals the differentiated response patterns of floods to climate change under different rainfall mechanisms, providing a scientific basis for regional flood control planning and risk management.
Journal Article
Effectiveness of Precursor Emission Reductions for the Control of Summertime Ozone and PM2.5 in the Beijing–Tianjin–Hebei Region under Different Meteorological Conditions
We used observed concentrations of air pollutants, reanalyzed meteorological parameters, and results from the Goddard Earth Observing System Chemical Transport Model to examine the relationships between concentrations of maximum daily 8-h average ozone (MDA8 O
3
), PM
2.5
(particulate matter with diameter of 2.5 µm or less), and PM
2.5
components and 2-m temperature (T2) or relative humidity (RH), as well as the effectiveness of precursor emission reductions on the control of O
3
and PM
2.5
in Beijing–Tianjin–Hebei (BTH) under different summertime temperature and humidity conditions. Both observed (simulated) MDA8 O
3
and PM
2.5
concentrations increased as T2 went up, with linear trends of 4.8 (3.2) ppb °C
−1
and 1.9 (1.5) µg m
−3
°C
−1
, respectively. Model results showed that the decreases in MDA8 O
3
from precursor emission reductions were more sensitive to T2 than to RH. Reducing a larger proportion of volatile organic compound (VOC) emissions at higher T2 was more effective for the control of summertime O
3
in BTH. For the control of summertime PM
2.5
in BTH, reducing nitrogen oxides (NO
x
) combined with a small proportion of VOCs was the best measure. The magnitude of reduction in PM
2.5
from reducing precursor emissions was more sensitive to RH than to T2, with the best efficiency at high RH. Results from this study are helpful for formulating effective policies to tackle O
3
and PM
2.5
pollution in BTH.
Journal Article