bluuebunny/crossref_metadata_2025 huggingface dataset:
Tuning Na adsorption on the edge of a graphitic nanopore by incorporating a functionalized-ligand and single-heteroatom dopant
Authors: Nenni  , Saputro Adhitya G. , Shukri Ganes , Mobarak Nadhratun Naiim , Aprilyanti Fine Dwinita , Nuruddin Ahmad , Dipojono Hermawan K.
Published: January 2023

The combination of oxygen functional groups and heteroatom dopants at zigzag and armchair edges successfully enhances the Na adsorption strength.
Copper-catalyzed oxidative direct C3-cyanoarylation of quinoxalin-2(1H)-onesviadenitrogenative ring-opening of 3-aminoindazoles
Authors: Mou Chen-Xu , Yuan Jin-Wei , Hu Qian , Han Bing-Jie , Yang Liang-Ru , Xiao Yong-Mei , Fan Lu-Lu , Zhang Shou-Ren , Qu Ling-Bo
Published: January 2023

A convenient and efficient copper-catalyzed oxidative C3-cyanoarylation of quinoxalin-2(1H)-ones is developed using 3-aminoindazoles as efficient arylating agentsviathe cleavage of two C–N bonds.
Preparation of TiO2/VOx, TiO2/SiO2, and VOx/SiO2 nanostructures by hydrothermal methods and determination of their magnetic properties
Authors: Hasham Mohammad Tamim Mohammad , Ay Burak , Kaya Dogan , Yildiz Emel , Ekicibil Ahmet
Published: January 2023

New nanostructures of TiO2/VOx, TiO2/SiO2, and VOx/SiO2 have been prepared via hydrothermal methods at different temperatures and times.
Zeolitic-imidazolate framework (ZIF-8)-based immobilized multi-enzymes integrated with a colorimetric sensor for cholesterol assay
Authors: Yang Ke , Chen Guoning , Wang Lu , Guo Miao , Xu Jiameng , Ma Yirong , Luo Zhimin , Zeng Aiguo , Fu Qiang
Published: January 2023

A catalytic system of co-immobilized enzymes (Chox&HRP@ZIF-8) with good stability and reusability based on cascade reaction was designed for the detection of cholesterol. The assay has been successfully applied to serum samples.
Synthesis, characterization and in vitro anticancer analysis of PEG-capped Mn-doped TiO2 nanoparticles against hepatocellular carcinoma cells
Authors: Vijayakumar G. , Leonard Hilary H. Jude , Nisha P. , Thangavel Elangovan , Sambasivam Sangaraju
Published: January 2023

A schematic diagram depicting the cancer theranostics applications of luminescent nanoparticles.
Cu(OAc)2-catalyzed hydrazination of cyclopropanols and late-stage transformation to 4,5-dihydropyrazoles
Authors: Zhang Kui , Wei Cong , Li Yan , Yao Yueyang , Song Liangliang , Jin Jia , Cai Lingchao
Published: January 2023

Promising in vitro antifungal activity was demonstrated by the hydrazine and 4,5-dihydropyrazole core structures.
Improved electronic interaction and dispersing effect derived from the F-doped TiO2support on RuOxto boost the electrocatalytic oxygen evolution performance
Authors: Jia Hongrui , Yang Xin , Meng Xiangshe , Zhang Guoxin , Li Guoqiang
Published: January 2023

F–TiO2is prepared and innovatively adopted to support RuOxnanoparticles for enhancing the OER stability, activity and noble-metal utilization.
Copper molybdenum sulfide (Cu2MoS4) nanoplates as a proficient electrocatalytic interface for enhancing the electrochemical redox signals of ofloxacin for detection in pharmaceutical samples
Authors: Phung Thi Lan Huong , Vu Ngoc Phan , Nguyen Tuan Anh , Nguyen Ngoc Huyen , Ngo Xuan Dinh , Bui Van Hoi , Le Ly T. , Nguyen Anh D. , Le Anh-Tuan
Published: January 2023

In this study, a novel electrochemical sensor for the accurate determination of ofloxacin in a pharmaceutical sample was developed using active-site-rich Cu2MoS4 nanoplates as an excellent electrocatalytic platform.
Cobalt(ii)–curcumin cysteine conjugate as c-MYC promoter G-quadruplex selective switch-on fluorescence probe
Authors: Dwivedi Awadesh Kumar , Jha Niki Sweta
Published: January 2023

We have synthesized a metal organic framework comprising a cobalt(ii) complex of a curcumin–cysteine conjugate (i.e., Co–CC) as a fluorescent probe for the detection of G-quadruplex DNA sequences.
Extraction techniques for bioactive compounds of cannabis
Authors: Sainz Martinez Aitor , Lanaridi Olga , Stagel Kristof , Halbwirth Heidi , Schnürch Michael , Bica-Schröder Katharina
Published: January 2023

The beneficial properties of bioactive compounds of cannabis has renewed the scientific interest in their recovery. This review presents the available extraction techniques for these valuable compounds, along with a discussion on reporting practices.
Durable and thermally switchable polysilsesquioxane adhesives via dynamic covalent bonds: effect of a crosslinker on reversible chemistry
Authors: Kang Seung Hyun , Seo Jin Young , Oh Hyeon Ji , Lee Jung-Hyun , Lee Albert S. , Baek Kyung-Youl
Published: January 2023

Thermally switchable ladder-like poly(silsesquioxane) (LPSQ) adhesives based on Diels–Alder reaction were prepared and utilized as reversible adhesion materials.
The Pausing Strategies in Chinese Preschool Children's Narratives
Authors: Liu Jiehan , Yu Fan , Feng Chen , Li Su
Published: January 2023

Purpose:

Language production, a dynamic process involving real-time language processing, is crucial for children's language and communication development. To explore the early development of children's real-time language production, this study investigated Chinese preschool children's pausing strategies in narratives and their associations with verbal working memory and vocabulary abilities.

Method:

A picture-elicited narrative task was employed. Sixty Mandarin-speaking children aged 4–5 years were asked to tell a story according to the book
Frog, Where Are You?
The pausing types and positions in narratives were coded and analyzed. Additionally, children's verbal working memory and vocabulary were measured.

Results:

The results showed that 4- to 5-year-old children prefer to use silent pauses and tend to produce pauses within clauses. The total frequency of pausing decreases with age and shows a significant gender difference. Girls prefer to use within-clause pauses, whereas boys prefer to use between-clause pauses. More importantly, children's pausing frequency is closely associated with their verbal working memory and vocabulary, in which working memory plays a more important role.

Conclusions:

This study is a first-step exploration of pausing strategies in 4- to 5-year-old Chinese children's narratives. The developmental characteristics of pausing strategies shown in typically developing children serve as a crucial reference for interventions for children with language deficits.
Unbound stars hold the key to young star cluster history
Authors: Arunima Arunima , Pfalzner Susanne , Govind Amith
Published: January 2023

Aims.Gaia delivers the positions and velocities of stars at an unprecedented precision. Therefore, for star clusters, there exists much higher confidence in whether a specific star is a member of a particular cluster or not. However, membership determination is still especially challenging for young star clusters. At ages 2−10 Myr, the gas is expelled, ending the star formation process and leading to their expansion, while at the same time, many former members become unbound. As a first step, we aim to assess the accuracy of the methods commonly used to distinguish between bound and unbound cluster members; after identifying the most suitable technique for this task, we wish to understand which of the two populations is more suited to provide insights into the initial configuration and the dynamical history of a cluster starting from its currently observed properties.

Methods. Here, we perform N-body simulations of the dynamics of such young star clusters. We investigate how cluster dynamics and observational limitations affect the recovered information about the cluster from a theoretical perspective.

Results. We find that the much-used method of distance and velocity cutoffs for membership determination often leads to false negatives and positives alike. Often observational studies focus on the stars remaining bound. However, bound stars quickly lose the memory of the pre-gas expulsion phase due to their ongoing interaction with their fellow cluster members. Our study shows that it is the unbound stars that hold the key to charting a cluster’s dynamic history. Backtracking unbound stars can provide the original cluster size and determine the time of gas expulsion – two parameters that are currently still poorly constrained. This information is lost in the bound population. In addition, former members are often better indicators for disc lifetimes or initial binary fractions. We apply the backtracking analysis, with varying success, to the clusters: Upper Scorpius and NGC 6530. For highly substructured clusters such as Upper Scorpius, backtracking to the individual subcluster centres will provide better results in future.
Nanofluids, micro-lubrications and machining process optimisations − a review
Authors: Chakule Rahul R. , Chaudhari Sharad S. , Chandratre Kailas V. , Patole Pralhad B. , Talmale Poonam S.
Published: January 2023

The lubrication is a prime requirement of metal cutting industries to assure high quality performance. The conventional technique of coolant flow is less economical and eco-friendly. Recently, nano fluids found better cutting fluid in machining due to potential thermal and heat transfer properties. The role of micro-lubrication techniques and process optimization are equally important for improving process performance. The literature review presents the findings of different researchers in the field of nano fluids and micro-lubrication techniques. The experimental studies were focused on better process performance using micro-lubrication techniques, especially nanofluid MQL with optimized process parameters. The thermal conductivity of water based TiO2 nano fluid shows improvement by 22% in base fluids. The case study discussed which is focused on preparation and characterization of nano fluid, experimental setup and optimization of process parameters by Jaya algorithm. Finally, application of nano fluid, and challenges during nano fluid preparation is identified. The scope of research work is recommended for further study to obtain an economical, eco-friendly manufacturing process.
Persistence in randomly switched Lotka-Volterra food chains
Authors: Bourquin Antoine
Published: January 2023

We consider a dynamical system obtained by the random switching betweenNLotka-Volterra food chains. Our key assumption will be that at least two vector fields only differ on the resources allocated to the growth rate of the first species. We will show that the existence of a positive equilibrium of the average vector field is equivalent to the persistence of all species. Under this condition, the semi-group converges exponentially quickly to a unique invariant probability measure on the positive orthant. If this condition fails to hold, we have two possibilities. The first possibility is the extinction case, in which a group of species becomes extinct exponentially quickly while the distribution of the remaining species converges weakly to another invariant probability measure. The second possibility is the critical case, in which there is a weaker form of persistence of some species, whilst some of the remaining become extinct exponentially quickly. We will also analyse the sensitivity of this model to the parameters.
Research on digital transformation of supply chain: research status and recommendations
Authors: Li Han , Zhang Qi
Published: January 2023

This paper studies the relevant literature of digital transformation of supply chain, and obtains the necessity of research on digital transformation of supply chain. we use the visualization tool CiteSpace to analyze several key directions of digital transformation of supply chain: technology support, driving factors, capabilities.
Harmony in Confucian thought and building a community of shared future for mankind
Authors: Wei Shijie
Published: January 2023

A community of shared future for mankind (CSFM) is a new type of international system of win-win cooperation, the essence of which is to advocate for the creation of a harmonious human society. This political concept has many views coming from traditional Confucian thought, especially Confucian ideals of harmony. Interpreting CSFM from the perspective of harmony in Confucian thought can improve understandings of community and accordingly enhance its construction.
Humanistic quality teaching reform of material science
Authors: Ma Zhuang , Cheng Zhifang , Gao Lihong , Zhang Hongmei
Published: January 2023

How to play the role of humanistic quality education in Material major courses? This paper discusses the design ideas and specific implementation methods of integrating Curriculum humanistic quality into the teaching of material science from three aspects: curriculum knowledge objectives and ability objective, strategies of curriculum teaching methods, course expected learning results. After humanistic quality teaching reform of the basic course of material science, professional knowledge points and ideological and political elements are integrated, and the teaching platform, students' real feelings and the power of humanistic quality elements are coordinated.
Understanding and reflecting on teacher development of private colleges and universities - A case of Guangdong University of Science and Technology
Authors: Li Jiayu
Published: January 2023

Private colleges and universities have become an important part of higher education system in China, but most of the full-time teachers in private colleges and universities are graduates of master’s degree. They are young, willing to study, and have new ideas and the spirit of a pathbreaker. What is lacking is that they do not master the laws of education and scientific research methods. Moreover, they are short of the practice of teaching and training of scientific research. In this paper, we proposed the countermeasures of teacher development that the government, university and teachers should do in Guangdong University of Science and Technology.
Urease and Carbonic Anhydrase Inhibitory Effect of Xanthones from Aspergillus nidulans, an Endophytic Fungus of Nyctanthes arbor-tristis
Authors: Sana Talea , Khan Majid , Jabeen Almas , Shams Sidrah , Hadda Taibi Ben , Begum Sabira , Siddiqui Bina Shaheen
Published: January 2023

Urease plays a major role in the pathogenesis of peptic and gastric ulcer and also causes acute pyelonephritis and development of infection-induced reactive arthritis. Carbonic anhydrases
(CA) cause pathological disorders such as epilepsy (CA I), glaucoma, gastritis, renal, pancreatic carcinomas, and malignant brain tumors (CA II). Although various synthetic urease and
carbonic anhydrase inhibitors are known, these have many side effects. Hence, present studies were undertaken on ethyl acetate extract of Aspergillus nidulans, an endophytic fungus
separated from the leaves of Nyctanthes arbor-tristis Linn. and led to the isolation of five furanoxanthones, sterigmatin (1), sterigmatocystin (3),
dihydrosterigmatocystin (4), oxisterigmatocystin C (5), acyl-hemiacetal sterigmatocystin (6), and a pyranoxanthone (2). Acetylation of 3 gave compound
O-acetyl sterigmatocystin (7). Their chemical structures were elucidated by 1H and 13C NMR and MS. The inhibitory effect of isolated compounds was
evaluated on urease and carbonic anhydrase (bCA II) enzymes in vitro. Compounds 3 and 6 showed significant urease inhibition (IC50 19 and 21 µM), while
other compounds exhibited varying degrees of urease inhibition (IC50 33 – 51 µM). Compounds 4, 6 and 7 exhibited significant inhibition of bCA II
(IC50 values 21, 25 and 18 µM respectively), compounds 1–3 displayed moderate inhibition (IC50 61, 76 and 31 µM respectively) while 5 showed no
inhibition. A mechanistic study of the most active urease inhibitors was also performed using enzyme kinetics and molecular docking. All compounds were found non-toxic on the NIH-3T3 cell
line.
Wie politisch neutral ist Forschung, wie neutral ist psychiatrische
Versorgung?
Authors: Steinert Tilman
Published: January 2023

Gewissheiten und Bequemlichkeiten der vergangenen Jahre und Jahrzehnte sind auf
breiter Front zerbröckelt, gesamtgesellschaftlich und nicht selten auch in
der individuellen biographischen Kontinuität. Allenthalben ist Umdenken,
Neubesinnung, Neuorientierung und Transformation angesagt. Und bei uns, in der
psychiatrischen Versorgung und der sie begleitenden universitären und
außeruniversitären Forschung? Gewiss, Herausforderungen gab und gibt
es viele, die Fachkräftesituation, die Personalbemessungsrichtlinie PPP-RL,
die Digitalisierung, die Integration zukünftiger Absolvent:innen des
Direktstudiengangs Psychotherapie, das stetige Wachsen der Forensischen Psychiatrie,
die Anpassung an die UN-Behindertenrechtskonvention, das Bundesteilhabegesetz und
andere mehr. Nicht zuletzt gab es auch durchaus dramatische Auswirkungen der
Covid-19-Pandemie in der psychiatrischen Versorgung. Alle diese Themen spiegeln sich
teilweise auch in den Originalarbeiten und Debatten dieser Zeitschrift wider. Aber
jenseits dieser fachbezogenen Themen – berühren uns die
Änderungen der Welt, in der wir leben, auch?
Synthesis and Properties of Methylene-Bridged [6]Cyclo-2,6-naphthylene
Authors: Kai Nobushige , Kono Hideya , Yagi Akiko , Itami Kenichiro
Published: January 2023

A novel structurally constrained nanobelt, methylene-bridged [6]cyclo-2,6-naphthylene ([6]MCN), has been synthesized by the nickel-mediated intramolecular aryl–aryl coupling of a triflated prism[6]arene. The structural and electronic properties of [6]MCN were revealed through NMR studies and photophysical measurements. In contrast to methylene-bridged [6]cycloparaphenylene, our previously synthesized benzene-based analogue, [6]MCN has a low strain energy (77.4 kcal·mol–1) and displays bright fluorescence (Φ = 0.20).
Divergent Functionalization of Alkynes Enabled by Organic Photoredox Catalysis
Authors: Nicewicz David A. , Zhu Zhengbo , Qian Siran
Published: January 2023

Direct functionalization of alkynes under oxidative conditions is challenging, as alkynes are usually recalcitrant towards typical oxidants. Herein, we communicate a strategy for the divergent functionalization of alkynes with photoexcited acridinium organic dyes, presumably via the formation of vinyl cation radicals as key intermediates. Based on the nature of the nucleophiles, different types of difunctionalized products were obtained in moderate to good yields. Addition of lithium Lewis acids resulted in a surprising reversal of diastereocontrol.
Nanomaterial Characterisation of Diluted Platina and Alcohol Control Samples
Authors: Rajendran E.S.
Published: January 2023

Background The healing effects of homeopathic ultra-high potencies (UHPs) have always been a puzzle for material science, though recent research papers have now characterised the nanomaterial nature of several such UHPs. This study aimed to analyse the material content of clinically used potencies of the homeopathic medicine Platina (platinum) compared with alcohol control samples.

Methods Potencies of Platina were analysed under dynamic light scattering (DLS), high resolution transmission electron microscopy (HRTEM) with energy dispersive spectroscopy (EDS) and selected area electron diffraction (SAED) to identify the nanomaterial content. As control samples, both unsuccussed and potencies of alcohol were analysed by using DLS and HRTEM.

Results Platina 30c to CM: Nanoparticles were identified under DLS (mean particle size varying from 1.3 nm in 30c to 6.5 nm in CM) and HRTEM (particle size varying from 3.31 to 12.7 nm in 30c to 1.94 to 8.54 nm in CM). EDS confirmed the presence of platinum in all the samples of Platina. SAED analysis of Platina 30c, 200c, 1M and 10M confirmed also the presence of platinum dioxide (PtO2). For control samples, DLS and the HRTEM analyses of pharmaceutical grade unsuccussed alcohol and potentized Alcohol (6c, 12c and 30c) did not show any particles.

Conclusion Homeopathic potentization generated NPs of platinum in ultra-dilutions. NPs in potencies of Platina showed platinum in EDS and PtO2 in SAED. Importantly, control samples of alcohol did not show the presence of particles under DLS or HRTEM.
BAY 81-8973 Efficacy and Safety in Previously Untreated and Minimally Treated Children with Severe Hemophilia A: The LEOPOLD Kids Trial
Authors: Ljung Rolf , Chan Anthony K. C. , Glosli Heidi , Afonja Olubunmi , Becker Bastian , Tseneklidou-Stoeter Despina , Mancuso Maria Elisa , Saulyte-Trakymiene Sonata , Kenet Gili
Published: January 2023

Introduction BAY 81–8973, a full-length recombinant factor VIII for hemophilia A treatment, has been extensively evaluated in previously treated patients in the LEOPOLD (Long-Term Efficacy Open-Label Program in Severe Hemophilia A Disease) clinical trials.

Aim To assess BAY 81–8973 efficacy and safety when used for bleed prophylaxis and treatment in previously untreated/minimally treated patients (PUPs/MTPs).

Methods In this phase III, multicenter, open-label, uncontrolled study, PUPs/MTPs (<6 years old) with severe hemophilia A received BAY 81–8973 (15–50 IU/kg) at least once weekly as prophylaxis. Primary efficacy endpoint was the annualized bleeding rate (ABR) within 48 hours after prophylaxis infusion. Adverse events and immunogenicity were assessed. Patients who developed inhibitors were offered immune tolerance induction (ITI) treatment in an optional extension phase.

Results Fifty-two patients were enrolled, with 43 patients (mean age: 13.6 months) treated. Median (interquartile range) ABR for all bleeds within 48 hours of prophylaxis infusion was 0.0 (0.0–1.8) among patients without inhibitors (n = 20) and 0.0 (0.0–2.2) among all patients. As expected, inhibitors were the most frequent treatment-related adverse event (high titer: 17 [39.5%] patients; low titer: 6 [13.9%] patients). Six of 12 patients who underwent ITI treatment in the extension phase (high titer [n = 5], low titer [n = 1]) achieved a negative inhibitor titer.

Conclusion BAY 81–8973 was effective for bleed prevention and treatment in PUPs/MTPs. The observed inhibitor rate was strongly influenced by a cluster of inhibitor cases, and consequently, slightly higher than in other PUP/MTP studies. Overall, the BAY 81–8973 benefit–risk profile remains unchanged and supported by ongoing safety surveillance. Immune tolerance can be achieved with BAY 81–8973.
The Saudi Consensus for the Management of Cancer-Associated Thromboembolism: A Modified Delphi-Based Study
Authors: Alsheef Mohammed , Bazarbashi Shouki , Warsi Ashraf , Alfraih Feras , Almoomen Abdualkreem , Osman Ahmed , Owaidah Tarek
Published: January 2023

Background Cancer is a well-known risk factor of preventable thromboembolic disease. This study aims to provide guidance on the prevention and management of cancer-associated thrombosis (CT) that tailors prophylactic and therapeutic options for medical and surgical oncology patients presenting to health care settings in Saudi Arabia.

Methods The present consensus was developed in concordance with the modified Delphi-based approach, which incorporates a face-to-face meeting between two voting rounds to gain experts' feedback on the proposed statements. All experts were either oncologists, hematologists, or hemato-oncologist with an active clinical and research profile in hemato-oncology.

Results The experts highlighted that the comparatively high incidence of inherited thrombophilia among the Saudi population may account for a higher CT burden in the Kingdom than in other parts of the world. However, due to the lack of literature that assesses CT in Saudi Arabia, primary venous thromboembolism prophylaxis should be tailored according to a valid risk assessment of cancer patients and should be implemented in routine practice. For hospitalized medical oncology patients, the experts agreed that prophylaxis with low-molecular-weight heparin (LMWH) should be offered, regardless of the presence of acute illness. For ambulatory medical oncology patients, LMWH or direct oral anticoagulants (DOACs) prophylaxis should be offered for high-risk patients. Concerning surgical patients, they agreed that all oncology patients undergoing surgery should be offered thromboprophylaxis. In terms of secondary prophylaxis, the experts recommended continuing a prophylactic dose of anticoagulant (LMWH or DOAC), for an appropriate period depending on the cancer type and stage. Finally, they also provided a set of statements on management of CT in Saudi Arabia.

Conclusion The present modified Delphi-based study combined the best available evidence and clinical experience with the current health care policies and settings in Saudi Arabia to build a consensus statement on the epidemiology, prevention, and management of CT.
Raman scattering technique allows for quick and accurate COVID-19 tests
Authors: Johnson-Groh Mara
Published: January 2023

Gold nanoparticles and nanoprobes help researchers sandwich virus particles for quick and accurate detections of COVID-19 infections.
Non-toxic liquid metal proves useful in rheological studies
Authors: Green Leigh Ann
Published: January 2023

Galinstan used to prevent edge fracture in rotational rheometers
Thermal conductivity of pink CVD diamond: Influence of nitrogen-related centers
Authors: Inyushkin A. V. , Taldenkov A. N. , Ralchenko V. G. , Shu Guoyang , Dai Bing , Bolshakov A. P. , Khomich A. A. , Ashkinazi E. E. , Boldyrev K. N. , Khomich A. V. , Han Jiecai , Konov V. I. , Zhu Jiaqi
Published: January 2023

Thermal conductivity κ(T) of single-crystal CVD diamond lightly doped (about 3 ppm) with nitrogen has been measured at temperatures from 5.7 to 410 K. The sample was carefully characterized by optical absorption and photoluminescence spectroscopy for the presence of impurities. Nine different optically active defects related with nitrogen, hydrogen, and silicon impurities have been identified and quantified. This pink-tint crystal showed a high thermal conductivity of 24.0±0.5 W cm−1 K−1 at room temperature, which is very close to the highest value ever measured at about 25 W cm−1 K−1 for diamonds of natural isotopic composition. At the same time, the κ(T) of the crystal showed strong suppression >10% at temperatures 6<T<120 K with a maximum decrease of 2.7 times at ≈40 K compared to high purity diamonds. This behavior of the conductivity is attributed to a phonon scattering by charge carriers bound to nitrogen-related impurity centers, which is ineffective, however, at room and higher temperatures. The κ(T) has been calculated within the model based on the Callaway theory taking into account the elastic phonon scattering off charge carriers (holes and electrons) in the ground states of doping centers, and a very good agreement between the measured and theoretical data has been achieved. The model also gives a good approximation to the experimental data for κ(T) given in the literature for synthetic and natural single-crystal diamonds.
Feasibility of seismic wave communication using electromagnetic vibrator under strong environmental noise interference: Field experimental research
Authors: Wang Kaikai , Jiang Tao , Li Shuang , Wang Xin , Hu Qiuyue , Qin Kai
Published: January 2023

Although various wired or wireless communication facilities play a significant role in underground mine production monitoring and disaster warning, some communication nodes will be damaged when an accident occurs, resulting in unreliable emergency communications. Due to the excellent transmission characteristics of seismic waves in the earth channel, there is no need for the seismic wave communication system to set up relay nodes. Since seismic waves are not easily disturbed by the external environment, they can be used as a new type of emergency communication carrier to realize information transmission. However, under strong background noise interference in a real environment, the feasibility of seismic wave communication using an electromagnetic vibrator is not yet known. Therefore, a field experiment research on electromagnetic vibrator seismic wave communication was conducted. First, the model of electromagnetic vibrator seismic wave communication was established. In addition, the on–off keying modulation method, the cross-correlation segment threshold demodulation method, and the noise suppression method based on the time–frequency characteristics of the carrier were introduced. Finally, an electromagnetic vibrator seismic wave communication system was built, and binary data communication up to 72 m without deploying additional relay nodes was achieved successfully. The experimental results illustrate the feasibility of the electromagnetic vibrator seismic wave communication under strong background noise interference in a real environment. Furthermore, combined with the characteristics of the seismic wave, the time–frequency slice filtering can significantly improve the signal-to-noise ratio of the seismic wave and can further increase the communication distance with respect to the traditional methods.
The prediction of contact force networks in granular materials based on graph neural networks
Authors: Li Zirui , Li Xingqiao , Zhang Hang , Huang Duan , Zhang Ling
Published: January 2023

The contact force network, usually organized inhomogeneously by the inter-particle forces on the bases of the contact network topologies, is essential to the rigidity and stability in amorphous solids. How to capture such a “backbone” is crucial to the understanding of various anomalous properties or behaviors in those materials, which remains a central challenge presently in physics, engineering, or material science. Here, we use a novel graph neural network to predict the contact force network in two-dimensional granular materials under uniaxial compression. With the edge classification model in the framework of the deep graph library, we show that the inter-particle contact forces can be accurately estimated purely from the knowledge of the static microstructures, which can be acquired from a discrete element method or directly visualized from experimental methods. By testing the granular packings with different structural disorders and pressure, we further demonstrate the robustness of the optimized graph neural network to changes in various model parameters. Our research tries to provide a new way of extracting the information about the inter-particle forces, which substantially improves the efficiency and reduces the costs compared to the traditional experiments.
Pressure-driven tearing and thermal transport in finite-beta reversed field pinch computations
Authors: Gupta U. , Sovinec C. R.
Published: January 2023

Nonlinear resistive-magnetohydrodynamics (MHD) computation with heating and anisotropic transport is applied to examine the interaction between thermal energy and magnetic fluctuations in inductively driven reversed-field pinches (RFPs). The magnetic fluctuations underlie magnetic field reversal through dynamo-like correlations, and they enhance thermal energy transport through fluctuations of parallel heat flux density. With the unfavorable magnetic curvature that exists across the RFP profile, thermal energy also affects the magnetic fluctuations. Computations with the NIMROD code [Sovinec et al., J. Comput. Phys. 195, 355–386 (2004)] integrate nonlinear MHD dynamics with energy transport and reproduce an RFP state with experimentally relevant values of plasma-β. Equilibria constructed from results of the 3D computations are analyzed to assess the sources of free energy in the saturated nonlinear state. Linear computations for these profiles show unstable modes of tearing parity. Their eigenfunctions are used to evaluate and compare stabilizing and destabilizing contributions to the kinetic energy integral. An assessment of the drives in the integral reveals that the pressure gradient drive is of comparable magnitude to the parallel current drive, and only the sum of the two surpasses the stabilizing contributions. Correlation of magnetic and parallel heat flux density fluctuations in the nonlinear computations shows that fluctuation-induced thermal conduction is the dominant mode of energy loss, as expected from experimental evidence. Decomposition of the fluctuating heat flux density shows that second-order correlations, alone, do not explain the total energy transport. Higher-order correlations are also important.
Tungsten-oxide/polypyrrole film for hybrid solid-state electrochromic smart window
Authors: Kandpal Suchita , Ghosh Tanushree , Rani Chanchal , Bansal Love , Tanwar Manushree , Kumar Rajesh
Published: January 2023

An organic–inorganic hybrid electrochromic device was fabricated by combining the films of hydrothermally synthesized tungsten oxide (WO3) with electrodeposited polypyrrole. Before making a device, these deposited thin films were characterized using scanning electron microscopy, infrared spectroscopy, and Raman spectroscopy techniques. Thereafter, a solid-state organic–inorganic electrochromic device was fabricated, which shows reversible switching between coloration and bleaching states with a very small external bias voltage (±1 V) and excellent cyclic stability up to 500 s with a negligible amount of transmission loss. In situ electrochemical studies show that the device has enhanced switching speed (1.1/1.8 s), and optical contrast of more than 47% at the wavelength of 650 nm. Furthermore, the optimized electrochromic device displays enhanced coloration efficiency up to ∼304 cm2/C. All these results open a new door for increasing the performance of a single-layered device by combining it with complementary electrodes.
Numerical simulations of flow around dual tandem circular cylinders under a strong axial magnetic field
Authors: Zhang Xiang-Fei , Yang Juan-Cheng , Ni Ming-Jiu , Zhang Nian-Mei , Yu Xin-Gang
Published: January 2023

This work is dedicated to understand the magnetohydrodynamic (MHD) flow around two identical tandem circular cylinders confined in a duct under external axial magnetic field. The influences of magnetic field (represented by the Hartmann number Ha), inlet velocity of conducting fluid (represented by the Reynolds number Re), and the gap ratio (L/d, the ratio of the distance between the centers of two cylinders to the diameter of the circular cylinder) on the flow regimes, vortex shedding frequency, pressure coefficients, drag coefficients, and pressure drop are investigated. The simulations are conducted in the parameter ranges 2≤L/d≤8, 180≤Re≤1440, and 101≤Ha≤1818, respectively. Four flow modes are observed, namely, no vortex shedding, single body, reattachment regime, and vortex shedding (VS) modes, with various Ha/Re2 and L/d values. For L/d>5, the flow field presents the VS flow model, a vortex street with synchronous periodic shedding appears behind the two cylinders, and the vortex shedding frequency matches well with that of the single one. The pressure coefficient shows different tendencies because of the arrangement of two circular cylinders. It can be found that the mean drag coefficients for the upstream circular cylinder and the downstream circular cylinder vary with Re/Ha0.8. For Re=361, Ha=504 and Re=722, Ha=1212, the flow field remains almost unchanged, which implies the balance between inertial force and Lorentz force because the inertial force would promote the flow, while the electromagnetic force leads to the reverse effect. Furthermore, the effects of magnetic field and inlet velocity of metal fluid on pressure drop ΔP between inlet and outlet can be fitted as a linear relation ΔP∼ReHa.
Toward more accurate adiabatic connection approach for multireference wavefunctions
Authors: Matoušek Mikuláš , Hapka Michał , Veis Libor , Pernal Katarzyna
Published: January 2023

A multiconfigurational adiabatic connection (AC) formalism is an attractive approach to compute the dynamic correlation within the complete active space self-consistent field and density matrix renormalization group (DMRG) models. Practical realizations of AC have been based on two approximations: (i) fixing one- and two-electron reduced density matrices (1- and 2-RDMs) at the zero-coupling constant limit and (ii) extended random phase approximation (ERPA). This work investigates the effect of removing the “fixed-RDM” approximation in AC. The analysis is carried out for two electronic Hamiltonian partitionings: the group product function- and the Dyall Hamiltonians. Exact reference AC integrands are generated from the DMRG full configuration interaction solver. Two AC models are investigated, employing either exact 1- and 2-RDMs or their second-order expansions in the coupling constant in the ERPA equations. Calculations for model molecules indicate that lifting the fixed-RDM approximation is a viable way toward improving the accuracy of existing AC approximations.
Non-adiabatic ring polymer molecular dynamics in the phase space of the SU(N) Lie group
Authors: Bossion Duncan , Chowdhury Sutirtha N. , Huo Pengfei
Published: January 2023

We derive the non-adiabatic ring polymer molecular dynamics (RPMD) approach in the phase space of the SU(N) Lie Group. This method, which we refer to as the spin mapping non-adiabatic RPMD (SM-NRPMD), is based on the spin-mapping formalism for the electronic degrees of freedom (DOFs) and ring polymer path-integral description for the nuclear DOFs. Using the Stratonovich–Weyl transform for the electronic DOFs and the Wigner transform for the nuclear DOFs, we derived an exact expression of the Kubo-transformed time-correlation function (TCF). We further derive the spin mapping non-adiabatic Matsubara dynamics using the Matsubara approximation that removes the high frequency nuclear normal modes in the TCF and derive the SM-NRPMD approach from the non-adiabatic Matsubara dynamics by discarding the imaginary part of the Liouvillian. The SM-NRPMD method has numerical advantages compared to the original NRPMD method based on the Meyer–Miller–Stock–Thoss (MMST) mapping formalism due to a more natural mapping using the SU(N) Lie Group that preserves the symmetry of the original system. We numerically compute the Kubo-transformed position auto-correlation function and electronic population correlation function for three-state model systems. The numerical results demonstrate the accuracy of the SM-NRPMD method, which outperforms the original MMST-based NRPMD. We envision that the SM-NRPMD method will be a powerful approach to simulate electronic non-adiabatic dynamics and nuclear quantum effects accurately.
Controlled generation of a vapor bubble representative of nucleate boiling conditions using transient focused laser heating
Authors: Dhillon Navdeep S. , Choudhary Dilipkumar , Maree Jayden , Inhelder Victor , Guadarrama Jazmin
Published: January 2023

Nucleate boiling is a phenomenon of significant importance in a broad range of industries. Increasing boiling performance parameters could lead to more efficient power plants and better electronics thermal management. However, difficulties associated with studying this extremely complex phenomenon have prevented a meaningful progress in the area of boiling heat transfer enhancement. In this paper, we implement a laser-based controlled bubble generation technique to enable accurate phenomenological studies of the boiling process. We present details of the transient focused-laser heating mechanism used to nucleate a microscale vapor embryo on the boiling surface. We present high-speed optical imaging data showing how this vapor embryo grows into a bubble using electrically applied background heat flux. Unlike the currently available artificial bubble generation approaches, which either generate unphysical bubbles or are extremely difficult to implement, we show that the laser-nucleated controlled single bubble demonstrates bubble ebullition characteristics closely representative of naturally occurring bubbles in nucleate pool boiling.
Photofragment imaging differentiates between one- and two-photon dissociation pathways in MgI+
Authors: Lockwood Schuyler P. , Metz Ricardo B.
Published: January 2023

The bond strength and photodissociation dynamics of MgI+ are determined by a combination of theory, photodissociation spectroscopy, and photofragment velocity map imaging. From 17 000 to 21 500 cm−1, the photodissociation spectrum of MgI+ is broad and unstructured; photofragment images in this region show perpendicular anisotropy, which is consistent with absorption to the repulsive wall of the (1) Ω = 1 or (2) Ω = 1 states followed by direct dissociation to ground state products Mg+ (2S) + I (2P3/2). Analysis of photofragment images taken at photon energies near the threshold gives a bond dissociation energy D0(Mg+-I) = 203.0 ± 1.8 kJ/mol (2.10 ± 0.02 eV; 17 000 ± 150 cm−1). At photon energies of 33 000–41 000 cm−1, exclusively I+ fragments are formed. Over most of this region, the formation of I+ is not energetically allowed via one-photon absorption from the ground state of MgI+. Images show the observed product is due to resonance enhanced two-photon dissociation. The photodissociation spectrum from 33 000 to 38 500 cm−1 shows vibrational structure, giving an average excited state vibrational spacing of 227 cm−1. This is consistent with absorption to the (3) Ω = 0+ state from ν = 0, 1 of the (1) Ω = 0+ ground state; from the (3) Ω = 0+ state, absorption of a second photon results in dissociation to Mg* (3P°J) + I+ (3PJ). From 38 500 to 41 000 cm−1, the spectrum is broad and unstructured. We attribute this region of the spectrum to one-photon dissociation of vibrationally hot MgI+ at low energy and ground state MgI+ at higher energy to form Mg (1S) + I+ (3PJ) products.
Numerical investigations of vortex dynamics and loss generation in the corner separation region of a high subsonic compressor blade
Authors: Wang Mingyang , Lu Xin'gen , Zhao Shengfeng , Zhang Yanfeng
Published: January 2023

Three-dimensional corner separation seriously deteriorates the aerodynamic performance of a compressor blade. In this study, the complicated vortex dynamics and loss mechanism in the corner region of a high subsonic compressor blade (the inlet Mach number is 0.67) are investigated using large eddy simulations (LESs) at a Reynolds number (Re) of 5.6 × 105. The results show that the predicted total pressure loss and outlet flow angle match well with the experimental data, indicating that the LES method can accurately predict the size and strength of corner separation in the compressor blade. With the passage vortex rolling up and further interacting with the low-momentum fluids originating from the end wall boundary layers and the local blade boundary layers, strong shear strain induces a large-scale concentrated shedding vortex (CSV) near the spanwise location of x/H = 0.3. The formation and rolling-up of the CSV not only cause the strongest flow blockage but also strengthen the turbulence anisotropy. As the CSV moves toward the trailing edge, the strong interaction with a pair of counter-rotating vortices shed in the wake region (wake shedding vortex) further accelerates the local generation of turbulent kinetic energy (TKE). Detailed TKE budget analysis shows that the streamwise Reynolds normal stress (w′w′¯) plays the most decisive role in the TKE production term. Furthermore, we demonstrate that the strength of turbulence anisotropy is positively correlated with the TKE budget. Therefore, turbulence anisotropy should be considered carefully in predicting the loss level in the corner region of a compressor blade.
Fourth-order stability analysis for capillary-gravity waves on finite-depth currents with constant vorticity
Authors: Dhar A. K. , Kirby James T.
Published: January 2023

We derive a fourth-order nonlinear evolution equation (NLEE) for narrow-banded Stokes wave in finite depth in the presence of surface tension and a mean flow with constant vorticity. The two-dimensional capillary-gravity wave motion on the surface of finite depth is considered here. The analysis is limited to one horizontal dimension, parallel to the direction of wave propagation, in order to take advantage of a formulation using potential flow theory. This evolution equation is then employed to examine the effect of vorticity on the Benjamin–Feir instability (BFI) of the Stokes capillary-gravity wave trains. It is found that the vorticity modifies significantly the modulational instability and in the case of finite depth, the combined effect of vorticity and capillarity is to enhance the instability growth rate influenced by capillarity when the vorticity is negative. The key point is that the present fourth-order analysis exhibits considerable deviations in the stability properties from the third-order analysis and gives better results consistent with the exact numerical results. Furthermore, the influence of linear shear current on Peregrine breather (PB) is studied.
Predicting the structures and vibrational spectra of molecular crystals containing large molecules with the generalized energy-based fragmentation approach
Authors: Hong Benkun , Fang Tao , Li Wei , Li Shuhua
Published: January 2023

The generalized energy-based fragmentation (GEBF) approach under periodic boundary conditions (PBCs) has been developed to facilitate calculations of molecular crystals containing large molecules. The PBC-GEBF approach can help predict structures and properties of molecular crystals at different theory levels by performing molecular quantum chemistry calculations on a series of non-periodic subsystems constructed from the studied systems. A more rigorous formula of the forces on translational vectors of molecular crystals was proposed and implemented, enabling more reliable predictions of crystal structures. Our benchmark results on several typical molecular crystals show that the PBC-GEBF approach could reproduce the forces on atoms and the translational vectors and the optimized crystal structures from the corresponding conventional periodic methods. The improved PBC-GEBF approach is then applied to predict the crystal structures and vibrational spectra of two molecular crystals containing large molecules. The PBC-GEBF approach can provide a satisfactory description on the crystal structure of a molecular crystal containing 312 atoms in a unit cell at density-fitting second-order Møller–Plesset perturbation theory and density functional theory (DFT) levels and the infrared vibrational spectra of another molecular crystal containing 864 atoms in a unit cell at the DFT level. The PBC-GEBF approach is expected to be a promising theoretical tool for electronic structure calculations on molecular crystals containing large molecules.
Exciton dispersion and exciton–phonon interaction in solids by time-dependent density functional theory
Authors: Liu Junyi , Lu Gang , Zhang Xu
Published: January 2023

Understanding, predicting, and ultimately controlling exciton band structure and exciton dynamics are central to diverse chemical and materials problems. Here, we have developed a first-principles method to determine exciton dispersion and exciton–phonon interaction in semiconducting and insulating solids based on time-dependent density functional theory. The first-principles method is formulated in planewave bases and pseudopotentials and can be used to compute exciton band structures, exciton charge density, ionic forces, the non-adiabatic coupling matrix between excitonic states, and the exciton–phonon coupling matrix. Based on the spinor formulation, the method enables self-consistent noncollinear calculations to capture spin-orbital coupling. Hybrid exchange-correlation functionals are incorporated to deal with long-range electron–hole interactions in solids. A sub-Hilbert space approximation is introduced to reduce the computational cost without loss of accuracy. For validations, we have applied the method to compute the exciton band structure and exciton–phonon coupling strength in transition metal dichalcogenide monolayers; both agree very well with the previous GW-Bethe–Salpeter equation and experimental results. This development paves the way for accurate determinations of exciton dynamics in a wide range of solid-state materials.