bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing hepatoprotective action: oxyberberine amorphous solid dispersion system targeting TLR4
Authors: Chen Tingting , Li Qingguo , Ai Gaoxiang , Huang Ziwei , Liu Jun , Zeng Lingfeng , Su Ziren , Dou Yaoxing
Published: June 2024

Oxyberberine (OBB) is a significant natural compound, with excellent hepatoprotective properties. However, the poor water solubility of OBB hinders its release and absorption thus resulting in low bioavailability. To overcome these drawbacks of OBB, amorphous spray-dried powders (ASDs) of OBB were formulated. The dissolution, characterizations, and pharmacokinetics of OBB-ASDs formulation were investigated, and its hepatoprotective action was disquisitive in the D-GalN/LPS-induced acute liver injury (ALI) mouse model. The characterizations of OBB-ASDs indicated that the crystalline form of OBB active pharmaceutical ingredients (API) was changed into an amorphous form in OBB-ASDs. More importantly, OBB-ASDs showed a higher bioavailability than OBB API. In addition, OBB-ASDs treatment restored abnormal histopathological changes, improved liver functions, and relieved hepatic inflammatory mediators and oxidative stress in ALI mice. The spray drying techniques produced an amorphous form of OBB, which could significantly enhance the bioavailability and exhibit excellent hepatoprotective effects, indicating that the OBB-ASDs can exhibit further potential in hepatoprotective drug delivery systems. Our results provide guidance for improving the bioavailability and pharmacological activities of other compounds, especially insoluble natural compounds. Meanwhile, the successful development of OBB-ASDs could shed new light on the research process of poorly soluble medicine.
Synergistic effects of Arctic amplification and Tibetan Plateau amplification on the Yangtze River Basin heatwaves
Authors: Dong Wei , Jia XiaoJing , Li XiuMing , Wu Renguang
Published: June 2024

Extreme heatwaves pose a significant threat to a wide range of environmental, ecological, and social systems. The rapid warming of the Arctic and the Tibetan Plateau (TP), which are the most prominent features in the Northern Hemisphere in the context of climate change, has significantly influenced mid-latitude extreme events in recent decades. This study utilizes observational data and numerical simulations to demonstrate that the variations in Arctic amplification (AA) and TP amplification (TA) play a crucial role in the interannual variability of summer heatwaves (HWs) in the Yangtze River Basin (YRB) (HWs_YRB) region. The HWs_YRB is associated with a zonally oriented barotropic high-pressure system anchored over the YRB region. The spatial distribution and intensity of the HWs_YRB are impacted by the synergistic effects of AA and TA, via a meridional atmospheric tripole pattern and double jets over East Asia. Furthermore, AA primarily impacts the geographical extent of the HWs_YRB, while TA plays a critical role in determining the intensity of the HWs_YRB. Our findings provide an innovative perspective on the linkage between the pronounced warming observed in the Arctic and TP and the occurrence of summer HWs_YRB, enhancing our comprehension of the climatic consequences of the rapid changes in these two geographical regions.
Deep learning to quantify care manipulation activities in neonatal intensive care units
Authors: Majeedi Abrar , McAdams Ryan M. , Kaur Ravneet , Gupta Shubham , Singh Harpreet , Li Yin
Published: June 2024

Early-life exposure to stress results in significantly increased risk of neurodevelopmental impairments with potential long-term effects into childhood and even adulthood. As a crucial step towards monitoring neonatal stress in neonatal intensive care units (NICUs), our study aims to quantify the duration, frequency, and physiological responses of care manipulation activities, based on bedside videos and physiological signals. Leveraging 289 h of video recordings and physiological data within 330 sessions collected from 27 neonates in 2 NICUs, we develop and evaluate a deep learning method to detect manipulation activities from the video, to estimate their duration and frequency, and to further integrate physiological signals for assessing their responses. With a 13.8% relative error tolerance for activity duration and frequency, our results were statistically equivalent to human annotations. Further, our method proved effective for estimating short-term physiological responses, for detecting activities with marked physiological deviations, and for quantifying the neonatal infant stressor scale scores.
Overview of Biodiesel Production Processes
Authors: Sanduni Kavindi A. , Mahinsasa Rathnayake B.
Published: June 2024

The global population and energy demand are rapidly growing, creating harmful environmental impacts such as climate change and acidification, due to undesirable pollutant emissions from increasing fossil fuel consumption. Hence green alternatives to energy sources are needed, and biofuels produced through eco-friendly approaches are attracting worldwide attention. Of the different kinds of biofuels available, researchers have identified biodiesel as one of the most promising alternatives, as it can be used as an alternative to petrodiesel. Fuel characteristics such as lower greenhouse gas emissions, higher biodegradability, minimal combustion toxicity, and compatibility with existing engines are reasons behind the growth of the biodiesel industry. A wide range of feedstocks from four different generations, i.e. edible and non-edible vegetable oils, animal fats, waste cooking oils, and algal biomass, are possible candidates for biodiesel production. Various production technologies, diverse reactions and separation and purification operations, and different types of catalysts have been employed in biodiesel production processes with a range of feedstocks. The quality and yield of biodiesel are affected by the feedstock type and amount, catalyst type and loading, molar ratio of alcohol to feedstock, and reaction conditions such as operating temperature and reaction time. This chapter presents an overview of the biodiesel production process, covering state-of-the-art processing technologies for biodiesel production, separation, and purification stages, and effects of process parameters on biodiesel production. Favorable processes for commercial-scale biodiesel production with higher quality and yields are compared and discussed.
Developments in Homogeneous Catalytic Processes
Authors: Alkahlawy Amal A.
Published: June 2024

Global communities are focusing on renewable energy as a result of the depletion of fossil fuel supplies and rising environmental concerns about their production and consumption. The use of sustainable liquid feedstocks in place of non-renewable fossil fuels to produce biofuel (biodiesel) offers a viable alternative for the near future. Because it is made primarily from expensive high-quality virgin oil, the cost of producing conventional biodiesel is greater than that of diesel made from petroleum. The most sustainable way for the production of commercial biodiesel includes the use of a liquid base to catalyze the transesterification of the oil and fat found in triglycerides with short-chain alcohols. The catalytic potential of several types of catalysts, including homogeneous and heterogeneous acid/basic and mixed catalysts, in the transesterification process is compared. Owing to their simplicity of use, homogeneous catalysts, such as H2SO4, NaOH, and KOH, can be classified as either acid or basic catalysts for transesterification processes. Additionally, homogeneous catalysts offer a high output of biodiesel in a shorter time. A detailed overview of the most recent developments in homogeneous catalytic processes in biodiesel production is provided in this chapter.
Development of Heterogeneous/Nanocatalysts in Biodiesel Production
Authors: Maleki Basir , Kamyab Hesam , Yusuf Mohammad
Published: June 2024

The application of fossil fuels has diminished recently owing to many drawbacks, such as increases in greenhouse gas production, enhanced environmental pollution, and depletion of fossil fuel sources, and biofuels such as biodiesel and bioethanol can be suitable alternatives. Biodiesel is a sustainable fuel that has attracted much attention in recent years. It can be generated by the reaction of a light alcohol (e.g. methanol) and oil using a suitable catalyst. Catalysis is evolving into a strategic vocation of science since it represents a novel route to alleviate the drawbacks of energy and sustainability. These issues are becoming major concerns of the global vision of societal challenges and the global economy. Myriad catalysts have been applied for biodiesel generation so far, including homogeneous, heterogeneous, and enzyme catalysts, among which heterogeneous/nanocatalysts have attracted considerable attention owing to their outstanding stability, high reusability, and excellent biodiesel yields. Heterogeneous catalysts also present a range of selectivity, excellent catalytic activity, and water adaptability. In this chapter, various types of efficient heterogeneous/nanocatalysts utilized in biodiesel production, mechanisms, synthesis techniques, comparisons with homogeneous catalysts, and advantages and disadvantages are considered.
Blending Strategies and Properties of Biodiesel
Authors: Omkaresh B. R. , Yatish K. V. , Prashanth G. K. , Pramoda K.
Published: June 2024

The increasing need for energy and the non-renewability of conventional diesel have led researchers to turn their attention to the development of alternative fuels. In this context, biodiesel and alcohols have gained recognition as promising oxygenated alternative fuel additives that can be used in modern diesel engines with minimal changes. In this chapter, vegetable oils blended with alcohols and diesel are analysed with respect to their properties for use in diesel engines, and the properties of biodiesel, alcohols, and pure diesel are also analysed. Biofuels are appropriate for diesel engines because of their physicochemical similarities to pure diesel. Alcohol and biodiesels have higher oxygen contents, which ensure complete combustion and less harmful emissions from engines. A decreased calorific value has a negative impact on engine efficiency. In the past, several volumetric blends of biodiesel and diesel were employed in diesel engines, but numerous studies have demonstrated that the B20 blend (20% biodiesel–80% diesel) provides the best performance and low emissions. Future fuels with ternary compositions of alcohol, biodiesel, and diesel have enormous potential. It is important to evaluate recent studies on the use of alcohols as fuel additives in the form of ternary blends. Therefore, this chapter is centred on how ternary blends affect a diesel engine’s ability to perform better, with low emissions. It was found that adding between 10 and 80% of biodiesel and between 5 and 45% of alcohol to diesel was the most appropriate solution.
Surface engineering of high-k polymeric dielectric layers with a fluorinated organic crosslinker for use in flexible-platform electronics
Authors: Ye Heqing , Kwon Hyeok-jin , Ryu Ka Yeon , Wu Kaibin , Park Jeongwan , Babita Giri , Kim Inae , Yang Chanwoo , Kong Hoyoul , Kim Se Hyun
Published: June 2024

High-k polymeric layers with UV-assisted organic azide fluorine-based crosslinkers lead to dramatic improvements in the electrical performance of OFETs and integrated devices.
β-CsHg2I5, a compound with rare [Hg2I5] dimers and large optical anisotropy
Authors: Kong Yingying , Wang Hongshan , Zhao Wang , Sun Qi , Li Junjie , Pan Shilie
Published: June 2024

A new phase transition Hg-based halide β-CsHg2I5 with a large birefringence (Δn = 0.132@1064 nm) has been designed and fabricated by a high-temperature solution method.
NIR-responsive porous gold nanorod dispersed in a 3D gelatin scaffold for stimulus-responsive drug release and synergistic therapy
Authors: Panda Snigdharani , Khan Irfan , Neekhra Suditi , Srivastava Rohit , Srivastava Sunita
Published: June 2024

Biodegradable porous nanomaterials have emerged as a promising avenue for tumor drug delivery owing to their capacity to encapsulate large quantities of drugs and their compatibility with biological systems.
Development of new dehydrocostuslactone derivatives for treatment of atopic dermatitis via inhibition of the NF-κB signaling pathway
Authors: Li Xiaoyi , Lu Cheng , Du Wenxia , Zou Qiuping , Wang Ruirui , Hu Chunyan , Li Yanping , Zhang Yi , Mao Zewei
Published: June 2024

A series of dehydrocostuslactone (DHCL) derivatives have been prepared with good anti-inflammatory activity for treatment of AD.
Synthesis of 2-fluorinated pyrazolo[1,5-a]pyridines via base- mediated [3+2] cycloaddition of N-aminopyridinium salts with gem-difluorostyrenes
Authors: Feng Yang , Wu Yuanyuan , Yue Zengjiang , Fu Ying , Du Zhengyin
Published: June 2024

A method for the construction of 2-fluoropyrazolo[1,5-a]pyridines through base-promoted [3+2] cycloaddition of N-aminopyridinium salts with gem-difluorostyrenes has been established.
Construction of pyrazolo[1,5-a]pyrimidines and pyrimido[1,2-b]indazoles with calcium carbide as an alkyne source
Authors: You Xinjie , Wang Botao , Wen Fei , Li Zheng
Published: June 2024

One-step construction of both 5-arylpyrazolo[1,5-a]pyrimidines and 2-arylpyrimido[1,2-b]indazoles using inexpensive, abundant and easy-to-handle calcium carbide as a solid alkyne source is depicted.
Catalytic transformations of alkenes via nickelacycles
Authors: Qian Meng-Ying , Zhang Kai-Xiang , Xiao Li-Jun
Published: June 2024

This review summarizes recent developments in nickel-catalyzed transformations of alkenes via nickelacycles, highlighting the advantages and challenges of this innovative strategy.
The impact of asteroseismically calibrated internal mixing on nucleosynthetic wind yields of massive stars
Authors: Brinkman Hannah E. , Roberti Lorenzo , Kemp Alex , Michielsen Mathias , Tkachenko Andrew , Aerts Conny
Published: June 2024

Context. Asteroseismology gives us the opportunity to look inside stars and determine their internal properties, such as the radius and mass of the convective core. Based on these observations, estimations can be made for the amount of the convective boundary mixing and envelope mixing of such stars and for the shape of the mixing profile in the envelope. However, these results are not typically included in stellar evolution models.

Aims. We aim to investigate the impact of varying convective boundary mixing and envelope mixing in a range based on asteroseismic modelling in stellar models up to the core collapse, both for the stellar structure and for the nucleosynthetic yields. In this first study, we focus on the pre-explosive evolution and we evolved the models to the final phases of carbon burning. This set of models is the first to implement envelope mixing based on internal gravity waves for the entire evolution of the star.

Methods. We used the MESA stellar evolution code to simulate stellar models with an initial mass of 20 M⊙ from zero-age main sequence up to a central core temperature of 109 K, which corresponds to the final phases of carbon burning. We varied the convective boundary mixing, implemented as ‘step-overshoot’, with the overshoot parameter (αov) in the range 0.05−0.4. We varied the amount of envelope mixing (log(Denv/cm2 s−1)) in the range 0−6 with a mixing profile based on internal gravity waves. To study the nucleosynthesis taking place in these stars in great detail, we used a large nuclear network of 212 isotopes from 1H to 66Zn.

Results. Enhanced mixing according to the asteroseismology of main-sequence stars, both at the convective core boundary and in the envelope, has significant effects on the nucleosynthetic wind yields. This is especially the case for 36Cl and 41Ca, whose wind yields increase by ten orders of magnitude compared to those of the models without enhance envelope mixing. Our evolutionary models beyond the main sequence diverge in yields from models based on rotational mixing, having longer helium-burning lifetimes and lighter helium-depleted cores.

Conclusions. We find that the asteroseismic ranges of internal mixing calibrated from core hydrogen-burning stars lead to similar wind yields as those resulting from the theory of rotational mixing. Adopting the seismic mixing levels beyond the main sequence, we find earlier transitions to radiative carbon burning compared to models based on rotational mixing because they have lower envelope mixing in that phase. This influences the compactness and the occurrence of shell mergers, which may affect the supernova properties and explosive nucleosynthesis.
Compaction during fragmentation and bouncing produces realistic dust grain porosities in protoplanetary discs
Authors: Michoulier Stéphane , Gonzalez Jean-François , Price Daniel J.
Published: June 2024

Context. In protoplanetary discs, micron-sized dust grows to form millimetre- to centimetre-sized pebbles but encounters several barriers during its evolution. Collisional fragmentation and radial drift impede further dust growth to planetesimal size. Fluffy grains have been hypothesised to solve these problems. While porosity leads to faster grain growth, the implied porosity values obtained from previous simulations were larger than suggested by observations.

Aims. In this paper, we study the influence of porosity on dust evolution, taking into account growth, bouncing, fragmentation, compaction, rotational disruption, and snow lines, in order to understand their impact on dust evolution.

Methods. We developed a module for porosity evolution for the 3D smoothed particle hydrodynamics code PHANTOM that accounts for dust growth and fragmentation. This mono-disperse model is integrated into both a 1D code and the 3D code to capture the overall evolution of dust and gas.

Results. We show that porosity helps dust growth and leads to the formation of larger solids than when considering compact grains, as predicted by previous work. Our simulations taking into account compaction during fragmentation show that large millimetre grains are still formed but are ten to 100 times more compact. Thus, millimetre sizes with typical filling factors of ~0.1 match the values measured on comets or via polarimetric observations of protoplanetary discs.
The fundamental plane of black hole activity for low-luminosity radio active galactic nuclei across 0 < z < 4
Authors: Wang Yijun , Wang Tao , Ho Luis C. , Zhong Yuxing , Luo Bin
Published: June 2024

Context. The fundamental plane of black hole activity describes the correlation between radio luminosity (LR), X-ray luminosity (LX), and black hole mass (MBH). It reflects a connection between the accretion disc and the jet. However, the dependence of the fundamental plane on various physical properties of active galactic nuclei (AGNs) and host galaxies remains unclear, especially for low-luminosity AGNs, which is important for understanding the accretion physics in AGNs.

Aims. Here, we explore the dependence of the fundamental plane on the radio loudness, Eddington-ratio (λEdd), redshift, and galaxy star formation properties (star-forming galaxies and quiescent galaxies) across 0.1 < z ≤ 4 for radio AGNs. Based on current deep and large surveys, our studies can extend to lower luminosities and higher redshifts.

Methods. From the deep and large multi-wavelength surveys in the GOODS-N, GOODS-S, and COSMOS/UltraVISTA fields, we constructed a large and homogeneous radio AGN sample consisting of 208 objects with available estimates for LR and LX. Then we divided the radio AGN sample into 141 radio-quiet AGNs and 67 radio-loud AGNs according to the radio loudness defined by the ratio of LR to LX, and explored the dependence of the fundamental plane on different physical properties of the two populations, separately.

Results. The ratio of LR to LX shows a bimodal distribution that is well described by two single Gaussian models. The cross point between these two Gaussian components corresponds to a radio-loudness threshold of log(LR/LX) =  − 2.73. The radio-quiet AGNs have a significantly larger Eddington ratio than the radio-loud AGNs. Our radio-quiet and radio-loud AGNs show a significantly different fundamental plane, which indicates a significant dependence of the fundamental plane on the radio loudness. For both radio-quiet and radio-loud AGNs, the fundamental plane shows a significant dependence on λEdd, but no dependence on redshift. The fundamental plane shows a significant dependence on the galaxy star formation properties for radio-quiet AGNs, while for radio-loud AGNs this dependence disappears.

Conclusions. The fundamental plane sheds important light on the accretion physics and X-ray emission origins of central engines. X-ray emission of radio-quiet AGNs at 0.01 < λEdd < 0.1 are produced by a combination of advection-dominated accretion flow (ADAF) and synchrotron radiation from the jet, while at 0.1 < λEdd < 1 they mainly follow the synchrotron jet model. The origins of X-ray emission of radio-loud AGNs are consistent with a combination of ADAF and the synchrotron jet model at λEdd < 0.01, agree with the synchrotron jet model at 0.01 < λEdd < 0.1, and follow a combination of the standard thin disc and a jet model at λEdd > 0.1.
Indications of an offset merger in Abell 3667
Authors: Omiya Y. , Nakazawa K. , Tamura T. , Akamatsu H. , Matsushita K. , Okabe N. , Sato K. , Fujita Y. , Gu L. , Simionescu A. , Ichinohe Y. , Riseley C. J. , Akahori T. , Ito D. , Sakai K. , Kurahara K.
Published: June 2024

Context. Cluster mergers are the most energetic events, releasing kinetic energies of up to 1064 erg and involving megaparsec(Mpc)-scale shocks in their intra-cluster medium (ICM). In merging clusters, cold fronts are frequently observed, which are characterized by temperature and density jumps while maintaining constant pressure. They, together with the overall morphology of the ICM, provide important information for our understanding of the merging structure, such as velocity, impact parameter, and mass.

Aims. Abell 3667 is a nearby (z = 0.056) merging cluster with a prominent cold front and a pair of two bright radio relics. Assuming a head-on merger, the origin of the cold front is often considered to be a remnant of the cluster core stripped by its surrounding ICM. Some authors have proposed an offset merger scenario in which the subcluster core rotates after the first core crossing. This scenario can reproduce features such as the cold front and a pair of radio relics. To distinguish between these scenarios, we reanalyzed the ICM distribution and measured the line-of-sight bulk ICM velocity using the XMM-Newton PN data.

Methods. We created an unsharp masked image to identify ICM features, and analyzed X-ray spectra to explore the ICM thermodynamical state. Applying the new XMM-Newton European Imaging Camera (EPIC)–PN calibration technique using background emission lines, the line-of-sight bulk ICM velocities were also measured.

Results. In the unsharp masked image, we identify several ICM features, some of which we detect for the first time. We confirm the cold front and note an enhanced region extending from the cold front to the west (named “CF-W tail”). There is an enhancement of the X-ray surface brightness extending from the first brightest cluster galaxy (BCG) to the cold front, which is named the “BCG-E tail”. The notable feature is a “RG1 vortex”, which is a clockwise vortex-like enhancement with a radius of about 250 kpc connecting the first BCG to the radio galaxy (RG1). It is particularly enhanced near the north of the 1st BCG, which is named the “BCG-N tail”. The thermodynamic maps show that the ICM of the RG1 vortex has a relatively high abundance of 0.5−0.6 solar compared to the surrounding regions. The ICM of the BCG-E tail also has a high abundance and low pseudo-entropy and can be interpreted as a remnant of the cluster core’s ICM. Including its arc-like shape, the RG1 vortex supports the idea that the ICM around the cluster center is rotating, which is natural for an offset merger scenario. The results of the line-of-sight bulk ICM velocity measurements show that the ICM around the BCG-N tail is redshifted with a velocity difference of 940 ± 440 km s−1 compared to the optical redshift of the first BCG. We obtain other indications of variations in the line-of-sight velocity of the ICM and discuss these in the context of an offset merger.
Successful Reablation Hemostasis for Needle Tract Bleeding Following Colorectal Liver Metastasis Percutaneous Microwave Ablation: A Case Report
Authors: Phothong Thanakorn , Janjindamai Phurich , Hongsakul Keerati , Laohawiriyakamol Supparerk
Published: June 2024

Percutaneous ablation is a well-established alternative treatment for colorectal liver metastasis. Major complications after percutaneous ablation are less common but can occur. Few intervention options for immediate hemostasis after percutaneous ablation have been described, with most involving embolization or surgery. Recently, a few reports have shown good results of percutaneous heat ablation for hemostasis in needle tract bleeding. We report a case involving a 78-year-old woman who developed needle tract bleeding immediately after percutaneous microwave ablation for colorectal liver metastasis. The bleeding was successfully controlled using a reablation technique.
Persuading the emperors: a quantitative historical analysis of political rhetoric in traditional China
Authors: Hong Ze , Chen Yuqi
Published: June 2024

The study of rhetoric has a long history in the Western intellectual tradition. However, only minimal efforts have been made to rigorously examine the cultural evolution of various rhetorical strategies in argumentation over time. In this study, we harness the power of fully digitized Chinese dynastic history to systematically analyze how different rhetorical strategies were used to persuade superiors throughout the past two millennia. By leveraging existing literature on Chinese rhetoric and argumentation styles, as well as engaging in extensive consultation with historians of ancient China, we identify and classify rhetorical strategies into distinct categories. We then examine their recorded success in persuasion and any temporal changes in frequency. Our findings point to a cumulative payoff-biased cultural evolution where later dynasties tend to demonstrate higher recorded persuasion success, with the notable exception of the Ming dynasty. Additionally, we detect a temporal decline in the frequency of rhetorical strategies associated with persuasion failures, such as analogy and the use of auspicious/inauspicious signs.
Regional differences of agricultural total factor carbon efficiency in China
Authors: Huang Xiuquan , Zhang Tao , Wang Xi , Zheng Jiansong , Xu Guoli , Wu Xiaoshan
Published: June 2024

China’s agriculture has struggled over the past century to produce more food to feed the country’s expanding population while also contending with high-intensity pollution. In order to support China’s transition to low-carbon agriculture more efficiently, it is important to improve the efficiency of agricultural carbon emissions. This study employs the biennial weight modified Russell model to investigate China’s agricultural total factor carbon efficiency (ATFCE) during 1999–2018 and its differences between the three agricultural functional zones (AFZs), including the grain-producing zone (GPZ), the grain balance zone (GBZ), and the main grain-selling zone (GSZ). The study found that the ATFCE in China was 0.761, a high value. GSZ (0.9865) had the highest ATFCE, followed by GBZ (0.7201) and GPZ (0.6666). ATFCE in China fell by approximately 25%, from 0.825 in 1999 to 0.6983 in 2018. Further, the provinces with the highest ATFCE included Tibet (0.9997), Hainan (0.9981), Shanghai (0.997), Beijing (0.9937), and Jiangsu (0.9924). Provinces with the lowest ATFCEs included Hubei (0.4743), Yunnan (0.4645), Hunan (0.441), Anhui (0.4295), Heilongjiang (0.4130), and Jiangxi (0.3354). In addition, the difference in ATFCE within the whole of China, GPZ, and GBZ generally widened during 1999–2018. There was a rise in all three inequalities between the three AFZs. The difference between GPZ and GBZ was the greatest among the three interregional differences. Finally, the difference between subregions was the largest source of the total difference (43.66%), followed by the difference within subregions (30.04%) and the intensity of transvariation (25.94%).
Suppression or promotion: research on the impact of industrial structure upgrading on urban economic resilience
Authors: Zhang Lu , Lin Guodong , Lyu Xiao , Su Wenjie
Published: June 2024

Industrial The upgrading of industrial structure, as the main means of urban economic transformation, plays a crucial role in the process of achieving urban economic resilience construction. We conducted a study on the nonlinear impact mechanism of industrial structure upgrading on urban economic resilience based on panel data from 267 prefecture-level and above-level cities and above in China from 2008 to 2021, using globalization as a threshold variable. The obtained results demonstrated the following: (1) there existed a significant nonlinear relationship between industrial structure upgrading and rationalization and urban economic resilience, with a significant double threshold effect. (2) A robustness test was performed by removing extreme values from the sample, controlling for the time series and individual interaction terms while considering control variables, which did not change the basic conclusions based on the model. This demonstrated that the threshold regression model constructed in this study is robust and reliable. (3) From a regional heterogeneity perspective, the impact of industrial structure upgrading on urban economic resilience varied among different regions. Notably, industrial structure upgrading imposed a significant double threshold effect on urban economic resilience in the eastern and central regions, manifested as an inverted U-shaped trend. In the northeastern region, there was only a single threshold effect with globalization as the threshold variable, which still occurred on the left side of the inverted U-shaped curve, while no threshold effect was observed in the western region.
Simulating nuclear magnetic resonance can help identify water and oil within porous rock
Authors: McConnon Aili
Published: June 2024

High-resolution digital rock core simulations provide accurate pore and structure information.
Induced motions on Carroll geometries
Authors: Marsot L
Published: June 2024

In this article, we consider some Carrollian dynamical systems as effective models on null hypersurfaces in a Lorentzian spacetime. We show that we can realize Carroll models from more usual ‘relativistic’ theories. In particular, we show how ambient null geodesics imply the classical ŉo Carroll motion’ and, more interestingly, we find that the ambient model of chiral fermions implies Hall motion on null hypersurfaces, in agreement with previous intrinsic Carroll results. We also show how Wigner–Souriau translations imply (apparent) Carroll motion, and how ambient particles with a non vanishing gyromagnetic ratio cannot have a Carrollian description.
Design optimization and experimental verification of ultrasonic stack for micro hot embossing of polymers
Authors: Abdel-Aleem Ahmed , Fath El-Bab Ahmed M R , Yoshino Masahiko , El-Hofy Hassan A , Hassan Mohsen A
Published: June 2024

Ultrasonic micro hot embossing (UMHE) is a prominent technique used in numerous sectors to produce micro parts since it is cheaper, faster, and more accurate. Amplitude uniformity is a crucial parameter in UMHE in order to manufacture micro parts with accurate dimensions and high-quality surfaces, even though limited research has been conducted on the uniformity of ultrasonic amplitude at the horn face during the embossing process. This paper presents an experimental and numerical study for designing an ultrasonic transducer and horn tailored to the micro hot embossing of polymer micro parts. A finite element (FE) simulation model combined with the Taguchi method has been developed to optimize the horn geometry and maximum amplitude uniformity. The Taguchi orthogonal array of 25 design runs has been generated and simulated using the developed FE modal analysis model, and then the optimized geometry was used to fabricate the horn. Applied torque and operating time calibrate and evaluate the transducer vibration characteristics. Experimental and simulation results revealed that the fabricated ultrasonic transducer and horn of a straight microfeature has a natural frequency of 28.8 kHz and has an 11 µm average peak-to-peak amplitude with 0.963 amplitude homogeneity along the microfeature face. The achieved frequency separation was greater than 0.85 kHz, whereas the gain ratio was 1.2. The design methodology developed in this paper showed great potential and has been numerically validated for various microfeature shapes across the horn face. Consequently, it can be applied to various ultrasonic applications beyond UMHE.
Avoiding lateral mode leakage in thin film lithium niobate waveguides for the generation of spectrally pure photons at telecom wavelengths
Authors: Arora Muskan , Chokkara Pranav , Lugani Jasleen
Published: June 2024

Photonic integrated optical components, notably straight waveguides, serve as pivotal elements for on-chip generation and manipulation of quantum states of light. In this work, we focus on optimizing waveguides based on lithium niobate on insulator (LNOI) to generate photon pairs at telecom wavelengths using spontaneous parametric down-conversion (SPDC). Specifically, we investigate lateral leakage for all possible SPDC processes involving type 0, type I, and type II phase matching conditions in an X-cut lithium niobate waveguide and provide a recipe to avoid leakage loss for the interacting photons. Furthermore, focusing on type II phase matching, we engineer the waveguide in the single-mode regime such that it also satisfies group index matching for generating spectrally pure single photons with high purity (99.33%). We also address fabrication imperfections of the optimized design and find that the spectral purity of the generated photons is robust to fabrication errors. This work offers guidance for the suitable selection of morphological parameters to obtain lossless, single-mode LNOI waveguides for building linear optical circuits and photon pair generation at telecom wavelengths using desired phase-matching conditions.
Ferromagnetic semiconductors in extended lanthanide wires
Authors: Fan Yi-Wei , Zhang Wei , Ge Ni-Na , Li Zhe
Published: June 2024

Exploring one-dimensional (1D) ferromagnetic chains with high magnetic transition temperatures and robust spin polarization is crucial for the development of next-generation spintronic devices. Here, we demonstrate a bottom-up approach to the design and assembly of a 1D ferromagnetic chain based on the magic sandwich cluster Ho2B8. The stability of Ho2B8 is rationalized by the large HOMO-LUMO gap (2.02 eV) and double σ + π aromaticity. Our results show that the 1D linear chain is an attractive ferromagnetic semiconductor with the valence band fully spin-polarized. The long-range ferromagnetic order with a 5 μ
B magnetization on each Ho atom retains up to 86 K, and it features a magnetic transition within a tiny compressive strain (5%). Furthermore, the 1D linear chain exhibits a sizable magnetic anisotropy energy up to 30 meV/atom, indicating a sufficient energy barrier to suppress the spin fluctuations. The present findings suggest that the magnetic lanthanide chain (Ho2B8)
n
is a prospective candidate for next-generation spintronic devices.
Identification of bi-harmonic periodic signal contaminated with Gaussian random noise by analysing high-order PDF moments
Authors: Steinwolf Alexander
Published: June 2024

When a periodic multi-harmonic signal is contaminated by a random noise, the identification of harmonic amplitudes can be performed from the autocorrelation function. However, the latter is not indicative of harmonic phases. Both the amplitudes and the phases can be determined by a time-synchronous averaging procedure, but this requires an accurate knowledge of the multi-harmonic component period obtained from a separate measurement that is not always readily available. Hence, there has been previous research to avoid the necessity of measuring the period and it is the approach followed by this paper. The methodology used is based on the fact that the presence of a periodic component makes the probability density function of the composite signal non-Gaussian. By equalizing the theoretical high-order moments of the composite signal to the corresponding moments calculated for the measured data record, a closed-form solution is derived for the amplitudes and the phases of the bi-harmonic component.
Online testing of extinction method of high-pressure natural gas oil mist based on light extinction
Authors: Lin Guangyao , Hu Fei , Liu Zhen , Ji Zhongli , Wang Deyu , Chen Junxian
Published: June 2024

This paper proposes a theoretical model and scheme for accurately measuring droplet concentration in high-pressure natural gas environments, aiming for precise, online measurement of lubricating oil mist. The model integrates droplet behavior, light extinction properties of the medium, and pressure, using the light extinction method. It applies the Debye Series Expansion of Mie scattering to improve the light extinction coefficient for mediums such as lubricating oil particles. Differential Optical Absorption Spectroscopy is used to calculate the extinction index of natural gas at different pressures. The study innovates by replacing the traditional parallel light path with a non-parallel path that focuses the light beam, countering beam diameter expansion due to gas pressure. Empirical testing shows the method’s accuracy in online oil mist testing under 10 MPa pressure, with less than 5% error compared to offline methods. This work paves the way for future high-pressure gas particle monitoring, particularly in the oil and natural gas sector.
Remaining useful life prediction of mechanical equipment based on time-series auto-correlation decomposition and CNN
Authors: Hu Guolei , Fu Song , Zhong Shisheng , Lin Lin , Liu Yikun , Zhang Sihao , Guo Feng
Published: June 2024

Remaining useful life (RUL) prediction can provide critical information for complex equipment health states (HSs) assessment. Historical long-term HS degradation trends and current short-term HS changes are two key factors affecting RUL prediction. However, most existing deep learning-based RUL prediction methods only consider learning short-term HS change features but ignore learning long-term HS degradation trend features, which limits to improvement of RUL prediction performance. To address this problem, this paper develops a RUL prediction framework based on a combination of time-series auto-correlation decomposition (TSACD) and convolutional neural network (CNN), which can learn both long-term and short-term features of mechanical equipment, so that achieves more robust and accurate RUL prediction. First, a novel TSACD method is proposed to extract historical long-term features from collected long-term monitoring data. The advantage of TSACD is to highlight the true signal by reinforcing periodic features through the Auto-Correlation mechanism and to separate pure trend components using a deep time-series decomposition architecture. Second, the long-term features are mapped to the same space as the short-term HS monitoring data using a group linear layer, which is intended to be aligned and fused with short-term monitoring data. Third, the fused features are fed into a CNN for RUL prediction. Finally, a series of comparison experiments on the C-MAPSS dataset and the XJTU-SY dataset validate the outstanding prognostic performance of the proposed method. The experimental results show that the proposed method outperforms the other RUL prediction methods.
Effect of array arrangement on acoustic levitation performance
Authors: Chen Yiwei , Qiao Boyang , Fan Shuyuan , Jiang Liangxu , Li Xinbo
Published: June 2024

Acoustic levitation manipulation technology holds significant potential for applications in chemistry, biology, medicine, and micro-robotics due to its contact-less, adaptability, and safety advantages. The use of ultrasonic phased array is widespread in acoustic levitation, and the arrangement of the array plays a crucial role in this process. This study investigates the impact of array arrangement on concave and planar arrays. The acoustic levitation performance of concave and planar arrays is analysed with the maximum acoustic radiation force (ARF) and levitation range. The results indicate that concave and planar arrays exhibit similar trends with height in terms of ARF and levitation range and having a maximum value (for concave array, R = 38 mm and H = 67 mm in the z-axis, R = 34 mm and H = 61 mm in the x-axis, and for planar array, H = 66 mm in the long side and H= 55 mm in the short side). However, each array type’s ARF and levitation range variety follow opposite trends, with a maximum value when R = 90 mm and H = 195 mm for concave array and H = 165 mm for planar array. Adjusting the inclination of the array makes it possible to enhance the ARF and expand the control range. Furthermore, the optimal operating region of a concave array is concentrated at the intersection of the spherical axis (R =
H/2 when varying the curvature and height, ϕ = φ when rotavating), while the planar array offers a broader range of manipulation due to its insensitivity to minor variations. This research reveals the influence of array arrangement on ARF and levitation range, providing valuable insights for designing and optimizing acoustic levitation devices.
Differential confocal effective measurement region extraction method based on dual measurement
Authors: Huang Caihong , Yuan Tao , Chen Junpeng
Published: June 2024

Aiming at the problem that the existing differential confocal measurement (DCM) method lacks the ability to decouple the differential signals from over-range the depth data, which in turn leads to measurement errors, this study proposes a differential confocal effective measurement region extraction method based on dual measurement (D-DCM). The first measurement is a double blur depth measurement, which is a coarse measurement, and the initial acquisition of the depth map is realized by applying a known Gaussian kernel blurring to the focal plane image and calculating the edge gradient ratios between the original image and the blurred image. This depth map is used to determine whether the depth of the measured sample in the field of view is within the differential confocal range and to segment it. The second measurement is a DCM, which is a fine measurement. The effective measurement area of the segmented image is second measured with high precision depth measurement. It is shown by single and multiple step heights experiments that the proposed D-DCM method can effectively solve the problem of decoupling the differential signal from the axial depth in differential confocal.
Measurement method of spherical radius size of differential planetary gear tooth surface based on 3D vision
Authors: Zhang Yuewei , Wei Honglei
Published: June 2024

In order to accurately measure the spherical radius dimensions of planetary gear tooth surfaces, we propose a non-contact measurement method based on 3D vision technology. Firstly, the point cloud data of the planetary gear captured by the laser 3D profiler is preprocessed, and the tooth surface point cloud is extracted. Next, based on the structural characteristics of the planetary gear tooth surface, a uniform slicing and sampling algorithm is used to extract circular contour points where the tooth surface point cloud intersects with the slicing planes. These points are then projected onto a two-dimensional plane, where an improved RANSAC algorithm is used to precisely fit each circular cross-section. Contour points associated with significant fitting errors are removed based on a set tolerance value. Finally, an improved differential evolution algorithm is used to perform a three-dimensional spherical fitting on the contour points that meet the tolerance criteria, achieving accurate measurement of the spherical radius of the planetary gear tooth surfaces. Experimental results demonstrate that the repeatability error of the proposed method is ±0.02 mm, with a maximum absolute error of 0.026 mm and an average measurement time of 4.76 s. The method exhibits high robustness and measurement accuracy, meeting practical engineering measurement requirements.
Critical non-Hermitian topology induced quantum sensing
Authors: Sarkar S , Ciccarello F , Carollo A , Bayat A
Published: June 2024

Non-Hermitian (NH) physics predicts open quantum system dynamics with unique topological features such as exceptional points and the NH skin effect. We show that this new paradigm of topological systems can serve as probes for bulk Hamiltonian parameters with quantum-enhanced sensitivity reaching Heisenberg scaling. Such enhancement occurs close to a spectral topological phase transition, where the entire spectrum undergoes a delocalization transition. We provide an explanation for this enhanced sensitivity based on the closing of point gap, which is a genuinely NH energy gap with no Hermitian counterpart. This establishes a direct connection between energy-gap closing and quantum enhancement in the NH realm. Our findings are demonstrated through several paradigmatic NH topological models in various dimensions and potential experimental implementations.
Green synthesis and characterisation of ZnO from citrus hystrix extracts for photocatalytic application
Authors: Lauthfi Muhammad Asyraf Al-Wafiy , Mohd Yusoff Mohd Zaki , Ahmad Kamil Suraya , Che Azurahanim Che Abdullah , Malek Mohd Firdaus
Published: June 2024

The purpose of this ongoing research project is to enhance the quality of zinc oxide (ZnO) powder synthesised through a green synthesis process using extracts from C. hystrix. The objective is to explore the potential of C. hystrix as a sustainable source for the production of ZnO nanoparticles with improved properties. Through a series of experimental procedures, including characterisation techniques such as x-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–vis spectroscopy, the synthesised ZnO powder’s structural, morphological, and optical properties are evaluated. Additionally, the photocatalytic activity of the biosynthesised ZnO powder is assessed for its effectiveness in degrading organic pollutants under UV illumination. By systematically optimising the synthesis parameters and understanding the underlying mechanisms, this research endeavours to contribute to the advancement of green synthesis approaches for producing high-quality ZnO nanoparticles that demonstrate enhanced performance, thereby fostering sustainable and eco-friendly nanomaterial synthesis processes. Following the successful production of eco-friendly ZnO through green synthesis, the optimum sample will undergo several experiments using a doping method with various chemical substances.