bluuebunny/crossref_metadata_2025 huggingface dataset:
Tubuloid culture enables long-term expansion of functional human kidney tubule epithelium from iPSC-derived organoids
Authors: Yousef Yengej Fjodor A. , Jansen Jitske , Ammerlaan Carola M. E. , Dilmen Emre , Pou Casellas Carla , Masereeuw Rosalinde , Hoenderop Joost G. , Smeets Bart , Rookmaaker Maarten B. , Verhaar Marianne C. , Clevers Hans
Published: February 2023

Kidney organoids generated from induced pluripotent stem cells (iPSC) have proven valuable for studies of kidney development, disease, and therapeutic screening. However, specific applications have been hampered by limited expansion capacity, immaturity, off-target cells, and inability to access the apical side. Here, we apply recently developed tubuloid protocols to purify and propagate kidney epithelium from d7+18 (post nephrogenesis) iPSC-derived organoids. The resulting ‘iPSC organoid-derived (iPSCod)’ tubuloids can be exponentially expanded for at least 2.5 mo, while retaining expression of important tubular transporters and segment-specific markers. This approach allows for selective propagation of the mature tubular epithelium, as immature cells, stroma, and undesirable off-target cells rapidly disappeared. iPSCod tubuloids provide easy apical access, which enabled functional evaluation and demonstration of essential secretion and electrolyte reabsorption processes. In conclusion, iPSCod tubuloids provide a different, complementary human kidney model that unlocks opportunities for functional characterization, disease modeling, and regenerative nephrology.
Lack of Paxillin phosphorylation promotes single-cell migration in vivo
Authors: Xue Qian , Varady Sophia R.S. , Waddell Trinity Q Alaka’i , Roman Mackenzie R. , Carrington James , Roh-Johnson Minna
Published: February 2023

Focal adhesions are structures that physically link the cell to the extracellular matrix for cell migration. Although cell culture studies have provided a wealth of information regarding focal adhesion biology, it is critical to understand how focal adhesions are dynamically regulated in their native environment. We developed a zebrafish system to visualize focal adhesion structures during single-cell migration in vivo. We find that a key site of phosphoregulation (Y118) on Paxillin exhibits reduced phosphorylation in migrating cells in vivo compared to in vitro. Furthermore, expression of a non-phosphorylatable version of Y118-Paxillin increases focal adhesion disassembly and promotes cell migration in vivo, despite inhibiting cell migration in vitro. Using a mouse model, we further find that the upstream kinase, focal adhesion kinase, is downregulated in cells in vivo, and cells expressing non-phosphorylatable Y118-Paxillin exhibit increased activation of the CRKII-DOCK180/RacGEF pathway. Our findings provide significant new insight into the intrinsic regulation of focal adhesions in cells migrating in their native environment.
Recent progress on polyphenylene oxide-based thermoset systems for high-performance copper-clad laminates
Authors: Qin Yijing , Yu Xueyi , Fang Zeming , He Xiao , Qu Muchao , Han Meng , Lu Dong , Xue Ke , Wang Ke
Published: February 2023

With the rapid development of electronic information technology in the 5G era towards high integration, short propagation delay, and elevated assembly temperatures, more academic and industrial attention has been focused on high-frequency and high-speed copper-clad laminates (CCLs). Compared with conventional polymeric matrices, thermoset polyphenylene oxide (PPO) has become one of the most attractive resins applied in high-performance CCLs (HPCCLs) because of its excellent comprehensive properties, including outstanding dielectric properties, high thermal stability, great processibility, and low moisture absorption, etc. This review focuses on the history of the development of PPO prepolymers/oligomers, PPO-based thermoset resin systems, and PPO/inorganic filler composites to optimize the dielectric constant, dielectric loss, thermal conductivity, coefficient of thermal expansion, and mechanical properties. Moreover, some current challenges of PPO-based thermoset systems have been identified, such as developing feasible solutions to ensure the anti-aging properties for long-term reliability under harsh environments of high temperature, high humidity, and even high-frequency electromagnetic radiation. In general, more in-depth investigations of PPO-based thermoset systems for HPCCLs are required in the future.
In materia implementation strategies of physical reservoir computing with memristive nanonetworks
Authors: Milano Gianluca , Montano Kevin , Ricciardi Carlo
Published: February 2023

Physical reservoir computing (RC) represents a computational framework that exploits information-processing capabilities of programmable matter, allowing the realization of energy-efficient neuromorphic hardware with fast learning and low training cost. Despite self-organized memristive networks have been demonstrated as physical reservoir able to extract relevant features from spatiotemporal input signals, multiterminal nanonetworks open the possibility for novel strategies of computing implementation. In this work, we report on implementation strategies of in materia RC with self-assembled memristive networks. Besides showing the spatiotemporal information processing capabilities of self-organized nanowire networks, we show through simulations that the emergent collective dynamics allows unconventional implementations of RC where the same electrodes can be used as both reservoir inputs and outputs. By comparing different implementation strategies on a digit recognition task, simulations show that the unconventional implementation allows a reduction of the hardware complexity without limiting computing capabilities, thus providing new insights for taking full advantage of in materia computing toward a rational design of neuromorphic systems.
Band offsets of ITO/amorphous GaO
x
heterojunction determined by x-ray photoemission spectra
Authors: Zhang Junlin , Yuan Yidie , Yang Xiutao , Zheng Yujie , Zhang Hongguo , Zeng Guanggen
Published: February 2023

The band offsets of heterojunctions formed between indium tin oxide (ITO) and amorphous gallium oxide (a-GaO
x
) of different stoichiometric ratios were measured by x-ray photoelectron spectroscopy using the Kraut method. a-GaO
x
films with different stoichiometric ratios were deposited on commercial ITO/quartz substrates using radio frequency magnetron sputtering by varying the Ar/O2 flux ratio. With the increase of oxygen flux in the reaction gas, the oxygen vacancy (VO) concentration of a-GaO
x
decreases and its bandgap increases from 5.2 eV to 5.32 eV, while the valence band offset of ITO/a-GaO
x
heterojunction changes from 0.29 ± 0.07 eV to −0.74 ± 0.06 eV and conduction band offset changes from 0.95 ± 0.085 to 2.10 ± 0.075 eV. The results indicate that the band alignment of ITO/a-GaO
x
heterojunction can change from type I to type II with the variation of Ga/O stoichiometric ratio, which can provide guidance for the design of their corresponding high-performance heterostructured devices.
Strong perpendicular anisotropic ferromagnet Fe3GeTe2/graphene van der Waals heterostructure
Authors: Zhao Bing , Karpiak Bogdan , Hoque Anamul Md , Dhagat Pallavi , Dash Saroj P
Published: February 2023

Two-dimensional magnets offer a new platform for exploring fundamental properties in van der Waals (vdW) heterostructures and their device applications. Here, we investigated heterostructure devices of itinerant metallic vdW ferromagnet Fe3GeTe2 (FGT) with monolayer chemical vapor deposited graphene. The anomalous Hall effect measurements of FGT Hall-bar devices exhibit robust ferromagnetism with strong perpendicular anisotropy at low temperatures. The electrical transport properties measured in FGT/graphene heterostructure devices exhibit a tunneling transport with weak temperature dependence. We assessed the suitability of such FGT/graphene heterostructures for spin injection and detection and investigated the presence of FGT on possible spin absorption and spin relaxation in the graphene channel. These findings will be useful for engineering spintronic devices based on vdW heterostructures.
A novel test rig for the investigation of roller-cage impact of a needle roller bearing
Authors: Shi Zhifeng , LIU Jing
Published: February 2023

The collisions between the roller and cage result in crack initiation and propagation leading to the fracture of the cage bridge. The impact forces applied to the needle roller-bearing cage bridge can change the cage's strain distribution, which is related to the relative speed of the roller and cage. In this work, a needle roller bearing roller-cage impact test rig is built to quantify cage strain and investigate the speed impacts on roller-cage impact forces. On the cage bridge, three crack sizes are machined and put on the needle roller bearing roller-cage impact test rig. The strain is measured by the strain gauge positioned on the cage. The encoder measures the shaft speed. The effects of impact speed and crack size on roller-cage impact force and cage deformation are investigated.
Adjustment for profile deviations of gear involute artefacts
Authors: Ling Ming , Ling Siying , Yu Dianqing , Wang Fengtao , Shi Zhaoyao , Wang Liding
Published: February 2023

Gear involute artefact (GIA) is a kind of measurement standard for calibrating the gear involute measuring instrument. To reduce the profile form deviations and the difference of the profile slope deviations between the opposite flanks (left and right flank) of GIA, the effect of installation eccentricity on the profile deviations is analysed, and an adjustment method for profile deviations of GIA by the eccentric installation is proposed. The difference of profile slope deviations between the opposite flanks of GIA with designed base circle radius r
b = 100 mm changes from 0.31 μm to 0.1 μm after the adjustment through the eccentricity of the mandrel. The difference of profile slope deviations between the opposite flanks of GIA with designed base circle radius r
b = 60cos20° mm changes from 0.77 μm to 0.12 μm after the adjustment through a kind of rotary stroke bearing with eccentricity, meanwhile, the profile form deviations are reduced from 0.53 μm to 0.34 μm (right flank) and 0.89 μm to 0.46 μm (left flank). This adjustment method could improve the used accuracy of GIA without improving the machining accuracy of the involute and changing the measurement process of the measurement standard of GIA.
Optical response of plasmonic silver nanoparticles after treatment by a warm microwave plasma jet
Authors: Trahan J , Profili J , Robert-Bigras G , Mitronika M , Richard-Plouet M , Stafford L
Published: February 2023

This work investigates the effect of plasma treatment on the morphology and composition of 15 × 15 mm2 silver nanoparticle (70–80 nm) thin films. The silver nanoparticles are deposited onto thermal silica (SiO2/Si) substrates by spin-coating, then they are treated by an open-to-air microwave argon plasma jet characterized by a neutral gas temperature of 2200 ± 200 K. Scanning electron microscopy analysis reveals that the number of isolated nanoparticles in the film sample decreases after exposure to multiple jet passes, and that polygonal structures with sharp corners and edges are produced. Similar structures with much rounder edges are obtained after conventional thermal annealing at temperatures up to 1300 K. Based on localized surface plasmon resonance analysis in the range of 350–800 nm, the main extinction band of silver nanoparticles experiences a redshift after treatment with the plasma jet or with thermal annealing. Moreover, both treatments induce surface oxidation of the nanoparticles, as evidenced by x-ray photoelectron spectroscopy. However, only the plasma-exposed samples exhibit a significant rise in the surface-enhanced Raman scattering (SERS) signal of oxidized silver at 960 cm−1. 29

×

29 μm2 mappings of hyperspectral Raman IMAging (RIMA) and multivariate curve resolution analysis by log-likelihood maximization demonstrate that the SERS signal is controlled by large-scale micrometer domains that exhibit sharp corners and edges.
Top-down synthesis and enhancing device adaptability of graphene quantum dots
Authors: Sun Fangyan , Ghosh Hrilina , Tan Zhongchao , Sivoththaman Siva
Published: February 2023

Quantum dots (QD) are rapidly making their way into several application sectors including optoelectronics, and there is a strong need to focus on non-toxic QDs. In this work, we have synthesized graphene QDs in the size range of 1.4–4.2 nm from inexpensive graphite by oxidative cleavage using a sulphuric and nitric acid mixture. A subsequent hydrogen peroxide oxidation step, investigated using two thermal budgets, has resulted in QDs with excellent photoluminescence (PL) intensity. Prolonged, higher temperature oxidation results in smaller size GQDs. X-ray photoelectron spectroscopy analysis confirmed the role of ·OH radicals in the oxidation process and Raman analysis revealed that the higher thermal budget oxidation results in lower defect density. To overcome the challenges in device adaptability due to the inherent acidity in the QDs, a post-synthesis neutralization process was devised. The neutralized GQDs were formed into a film to be used as the active layer in a photodetector device. Fluorescence decay analysis showed there is no significant change in lifetime because of the film formation process. The fabricated GQD photodetector device exhibited high photocurrent under ultraviolet illumination with an ON/OFF ratio of 400% at an applied bias of ±1 V. The device performance underlines the high potential for the non-toxic, top-down synthesized GQDs for application in optoelectronic devices.
Experimental study of endurance characteristics of Al-doped HfO2 ferroelectric capacitor
Authors: Choi Yejoo , Shin Jaemin , Moon Seungjun , Min Jinhong , Han Changwoo , Shin Changhwan
Published: February 2023

In this work, the endurance characteristics of Al-doped HfO2 (HAO)-based metal-ferroelectric-metal (MFM) capacitors (which were annealed at 1000 °C) with various doping concentrations were investigated. The doping concentration was optimized for the high annealing temperature (1000 °C) process. To investigate the impact of cycling pulses on the endurance characteristics of HAO-based MFM capacitor, the rise/fall time (t

r/f
) and hold time (th
) for the cycling pulses were varied. Moreover, by adopting the recoverable fatigue process, the endurance characteristics under repetitive wake-up/fatigue processes were studied. The HAO capacitors achieved the remnant polarization (2Pr) of 23.767 μC cm−2 at pristine state under the high annealing temperature. Furthermore, it was demonstrated that the endurance characteristics (∼108 cycles) of the HAO capacitors were comparable to them of other HfO2-based ferroelectric capacitors. Lastly but not least, it turned out that the amount of oxygen and oxygen vacancies in the HAO thin film was dependent of doping concentrations for the film. The impact of oxygen and oxygen vacancies was quantitatively analyzed, in detail, with TEM, XPS and GIXRD analysis.
Takens-type reconstruction theorems of one-sided dynamical systems
Authors: Kato Hisao
Published: February 2023

The reconstruction theorem deals with dynamical systems that are given by a map

T
:
X
→
X

of a compact metric space X together with an observable

f
:
X
→

R

from X to the real line

R

. In 1981, by use of Whitney’s embedding theorem, Takens proved that if

T
:
M
→
M

is a (two-sided) diffeomorphism on a compact smooth manifold M with

dim
M
=
d

, for generic (T, f) there is a bijection between elements

x
∈
M

and corresponding sequence

(
f
T

j

(
x
)

)

j
=
0

2
d

, and moreover, in 2002 Takens proved a generalised version for endomorphisms. In natural sciences and physical engineering, there has been an increase in importance of fractal sets and more complicated spaces, and also in mathematics, many topological and dynamical properties and stochastic analysis of such spaces have been studied. In the present paper, by use of some topological methods we extend the Takens’ reconstruction theorems of compact smooth manifolds to reconstruction theorems of ‘non-invertible’ dynamical systems for a large class of compact metric spaces, which contains PL-manifolds, manifolds with branched structures and some fractal sets, e.g. Menger manifolds, Sierpiński carpet and Sierpiński gasket and dendrites, etc.
Existence, nonexistence and uniqueness for Lane–Emden type fully nonlinear systems
Authors: Maia Liliane , Nornberg Gabrielle , Pacella Filomena
Published: February 2023

We study existence, nonexistence, and uniqueness of positive radial solutions for a class of nonlinear systems driven by Pucci extremal operators under a Lane–Emden coupling configuration. Our results are based on the analysis of the associated quadratic dynamical system and energy methods. For both regular and exterior domain radial solutions we obtain new regions of existence and nonexistence. Besides, we show an exclusion principle for regular solutions, either in

R

N

or in a ball, by exploiting the uniqueness of trajectories produced by the flow. In particular, for the standard Lane–Emden system involving the Laplacian operator, we prove that the critical hyperbola of regular radial positive solutions is also the threshold for existence and nonexistence of radial exterior domain solutions with Neumann boundary condition. As a byproduct, singular solutions with fast decay at infinity are also found.
Collaborative data collection: shifting focus on meaning making during practical work
Authors: Pols Freek , Diepenbroek Patrick
Published: February 2023

In practical work focussing on conceptual development, students spend valuable in-class time on collecting data rather than making sense out of it. This provides a barrier to learning about the targeted concept. To address this problem, we developed an approach that we coin collaborative data collection. Using a practical on the topic density, we describe this approach and illustrate how the focus of practical work shifts away from mere data-collection towards meaning making. Although a single practical is described, the approach can be applied to other practicals as well.
Transition mechanisms between selective O3 and NO
x
generation modes in atmospheric-pressure plasmas: decoupling specific discharge energy and gas temperature effects
Authors: Liu Kun , Geng Wenqiang , Zhou Xiongfeng , Duan Qingsong , Zheng Zhenfeng , Ostrikov Kostya (Ken)
Published: February 2023

Two modes of the atmospheric-pressure plasma discharge, distinguished by the dominant O3 and NO
x
species are studied numerically and experimentally. To investigate the mode transition mechanisms, here we develop a global chemical kinetics model for the atmospheric-pressure dielectric barrier discharge involving 63 species and 750 reactions. Validated by the experimental results, the model accurately describes the mode transition. The N, O, O2(a), and O2(b) are the essential transient intermediate species for the O3 and NO
x
production and loss reactions. The individual and synergistic effects of the specific discharge energy and the gas temperature on the species density and the relative contributions of the dominant reactions are quantified under the increasing discharge voltage conditions. The modeling results indicate that the gas temperature and specific discharge energy both contributed to the discharge mode transition, while the decisive factors affecting the change of the O3 and NO
x
density are different in the respective modes. These insights contribute to diverse plasma applications in biomedicine, agriculture, food, and other fields where selective and controlled production of O3 and NO
x
species is the key for the desired plasma performance.
Phase diagram, band structure and density of states in two-dimensional attractive Fermi-Hubbard model with Rashba spin-orbit coupling
Authors: Han Rui , Yuan Feng , Zhao Huaisong
Published: February 2023

Based on the two-dimensional (2D) attractive Fermi-Hubbard model with Rashba spin–orbit coupling (SOC), the SOC strength and Zeeman field dependences of the phase diagram are investigated by calculating the pairing gap self-consistently. The results reveal that the phase transition from the BCS superfluid to the topological superfluid happens under proper Zeeman field strength and SOC strength. In particular, in contrast to the BCS superfluid decreasing monotonically as the SOC strength increasing, the topological superfluid region shows a dome with the SOC strength increasing. An optimal region in the phase diagram to find the topological superfluid can be found, which is important to realize the topological superfluid in optical lattice experimentally. Then we obtain the change of both band structure and density of states (DOSs) during the topological phase transition, and explain the four peaks of DOS in the topological superfluid by the topology change of the low-energy branch of quasiparticle energy spectra. Moreover, the topological superfluid can be suppressed by the doping concentration.
On the angular momentum of compact binary coalescence
Authors: He Xiaokai , Wu Xiaoning , Xie Naqing
Published: February 2023

The supertranslation ambiguity issue of angular momentum is a long-standing problem in general relativity. Recently, there appeared the first definition of angular momentum at null infinity that is supertranslation invariant. However, in the compact binary coalescence community, supertranslation ambiguity is often ignored. This paper demonstrates that we have the happy circumstance that the newly defined angular momentum coincides with the classical definition at the quadrupole level.
Study of parity violation in

and

decays*
Authors: Hong Peng-Cheng , Yan Fang , Ping Rong-Gang , Luo Tao
Published: February 2023

CP violation in baryonic decays has not been significantly observed. With large data events accumulated at

colliders or the Large Hadron Collider, charmed baryon decays would provide a promising laboratory to test CP symmetry. In this study, we formulate

and

decays for the measurement of their asymmetry parameters in weak decays at the BESIII or LHCb experiments. The polarization transfer is analyzed in the two processes of

and

, and the formulas for the joint angular distribution of these processes are provided. The sensitivity of the measurement of the asymmetry parameters of the above two decay processes is estimated for future experiments.
Integrated deep learning framework for unstable event identification and disruption prediction of tokamak plasmas
Authors: Zhu J.X. , Rea C. , Granetz R.S. , Marmar E.S. , Sweeney R. , Montes K. , Tinguely R.A.
Published: February 2023

The ability to identify underlying disruption precursors is key to disruption avoidance. In this paper, we present an integrated deep learning (DL) based model that combines disruption prediction with the identification of several disruption precursors like rotating modes, locked modes, H-to-L back transitions and radiative collapses. The first part of our study demonstrates that the DL-based unstable event identifier trained on 160 manually labeled DIII-D shots can achieve, on average, 84% event identification rate of various frequent unstable events (like H-L back transition, locked mode, radiative collapse, rotating MHD mode, large sawtooth crash), and the trained identifier can be adapted to label unseen discharges, thus expanding the original manually labeled database. Based on these results, the integrated DL-based framework is developed using a combined database of manually labeled and automatically labeled DIII-D data, and it shows state-of-the-art (AUC = 0.940) disruption prediction and event identification abilities on DIII-D. Through cross-machine numerical disruption prediction studies using this new integrated model and leveraging the C-Mod, DIII-D, and EAST disruption warning databases, we demonstrate the improved cross-machine disruption prediction ability and extended warning time of the new model compared with a baseline predictor. In addition, the trained integrated model shows qualitatively good cross-machine event identification ability. Given a labeled dataset, the strategy presented in this paper, i.e. one that combines a disruption predictor with an event identifier module, can be applied to upgrade any neural network based disruption predictor. The results presented here inform possible development strategies of machine learning based disruption avoidance algorithms for future tokamaks and highlight the importance of building comprehensive databases with unstable event information on current machines.
The Types and Equations of Diesel Spray Angle Curve under Cloud Cavitation and Hydraulic Flip
Authors: Yu Yang , Zhang Xiao
Published: February 2023

For the five types of angle profile curve and possible low spray angles in the unsteady state of diesel spray, all the possible corresponding conditions are given and their curve regression equations can be established by experiments and deep learning methods proposed in this paper. The initial pressure rises sharply with the axial velocity difference significant so that we can infer the relatively large radial disturbance is also as an important reason for cloud cavitation formation. At the moment it is difficult to form wall-adherent cavitation and further develop into supercavitation and hydraulic flip and the too large spray angle is formed in the non-steady phase. And the closer to the maximum position the needle valve is, the slower the velocity increases. So there is a significant decline in the later period, which is caused by gradual cloud cavitation weakening. Especially after entering the steady phase, both angle and its variation range are much smaller, indicating that it is mainly affected by the disturbed flow due to the in-nozzle gas under hydraulic flip developing from wall-adherent cavitation. Besides, the experiment the results of cross-sectional, spatial, and three-dimensional detailed distribution under cloud cavitation should also be further developed through X-ray.
Experimental Study on Rheological Properties of Temporary Storage Sludge
Authors: Wu Tengwei , Liu Mingming , Guo Tao
Published: February 2023

In order to master the rheological properties of temporary sludge, the sludge in Shanghai Laogang temporary storage area was sampled, and the rheological properties test was carried out. The effects of temperature, solid content and other parameters on the rheological properties of sludge were analyzed. Based on the above research and analysis results, the key parameters that affect the rheological properties of sewage sludge were analyzed, and combined with previous research conclusions, the methods such as summary and numerical fitting were used. The sludge function expression of the rheological characteristics of the temporary storage sludge is obtained, which provides theoretical guidance for the transport of sludge in the temporary storage area.
Effects of Blended Biodiesel Coupled with Miller Cycle on Combustion and Emissions of Marine Diesel Engines
Authors: Zhang Feifei , Lin Hang , Wang Qiwei , Chen Jian , Ye Zixiao , Fan Jinyu , Li Pinfang , Huang Jialiang
Published: February 2023

In order to study the effect of blended biodiesel coupled Miller cycle technology on the combustion and emission performance of diesel engine, the 4190 diesel engine was simulated by AVL-FIRE software. The Miller degree and different blending ratios of biodiesel are simulated and analyzed. The results show that: under the same Miller degree, with the increase of the blending ratio, the explosion pressure decreases significantly, the cylinder temperature decreases, the CO emission decreases significantly, and the NO emission increases. Soot emissions have dropped significantly. Under the same blending ratio, with the increase of Miller degree, the explosion pressure increases, the cylinder temperature decreases gradually but not obviously, the CO emission decreases, the NO emission increases first and then decreases, and the Soot emission decreases. Therefore, selecting the appropriate blending ratio and Miller degree can better reduce NO emissions, and at the same time have a better inhibitory effect on the generation of Soot and CO, and the power performance of the diesel engine is slightly improved. The results of this study provide a solution for the practical application of biodiesel.
Preparation and Photocatalysis Characteristics of Flower-like ZnO by Microwave Method
Authors: Cai Yungao , Huang Jinwen
Published: February 2023

Flower-like ZnO was prepared by a simple and efficient microwave method at different microwave times. The effect of microwave time on the structure and morphology of the flower-like ZnO was analyzed systematically by XRD, SEM, PL and other equipment, the photocatalysis properties of flower-like ZnO were analyzed systematically through the degradation effect of ZnO on methyl orange. With the increase of microwave time, the shape of flower-ZnO was changed, it was bud at 10 min, then became flower-like gradually, and stacked reunion at 40 min. photoluminescence results showed green emission peaks at 536nm, photoluminescence intensity of ZnO prepared at 20 min was weakest, the photocatalytic efficiency of ZnO were not the same at different times, photocatalytic efficiency of ZnO prepared at 20 min and 40 min were 67% and 58.3% respectively, and photocatalytic efficiency of ZnO prepared at 10 min, 15 min, 30 min were 86.7%, 87.1%, 82.1% respectively.
Forming Mechanism Analysis for an Aircraft Titanium Alloy Tubular Form-fit Joint Fabricated by Internal Rolling
Authors: Cao Jindou , Yang Jingchao , Hu Shitian , Men Xiangnan , Cui Baojin , Yu Jinping , Yang Yan , Fang Senpeng
Published: February 2023

Titanium alloy tubular form-fit joints formed by internal rolling have the advantages of high-pressure resistance and high reliability, and it is a promising technology to prevent the leakage occurred in aircraft pipeline system. Based on the material modeling for the joined titanium alloy tube and process modeling for the internal rolling, this paper established finite element models to simulate the whole forming process of tubular form-fit joint with loading and unloading. According to the simulation results, the distribution characteristics of stress and plastic strain along two axial paths were analyzed under different forming parameters. Finally, a reasonable ranges of process window were obtained, which are 0.27~0.3mm of rolling depth and 63~68 in•lbs of roller torque.
Facile Preparation of Superhydrophobic and Flame-Retardant Cotton Fabrics
Authors: Yu Luyan , Xiong Ying , Zou Longkun , Zhao Yuhui , Li Shiwei , Bi Shuguang
Published: February 2023

The cotton textiles with superhydrophobic and flame-retardant properties used in this study were manufactured by combining nano APP@SiO2 with silicone oil. To generate nano APP@SiO2 particles, the APP is coated with nano SiO2. The nano APP@SiO2 improves the flame retardancy of cotton textiles while altering the surface roughness of cotton fabrics, making them superhydrophobic after being treated with silicone oil. Cotton fabrics’ surface topography, chemical components, crystalline structure, thermal stability, flame-retardant, and superhydrophobic properties were investigated. The modified cotton fabric demonstrated not only exceptional superhydrophobicity with a WCA of 151.28°, but also good flame-retardant property. This multifunctional cotton fabric offers a wide range of commercial applications.
Effect of Boron on Mechanical Properties and Fatigue Life of Spring Steel for Automobile Suspension
Authors: Hu Yang
Published: February 2023

Three Si-killed 55SiCrA suspension spring steels with different boron contents (0, 23 ppm and 43 ppm) were obtained by vacuum induction levitation melting furnace. Through hot tensile, torsional Bauschinger and rotating bending fatigue tests, the microstructure, precipitate, tensile strength, percentage of area reduction, elastic sag resistance and fatigue life of spring steel were analyzed, respectively. Boron accelerated the dynamic recrystallization at 800 ºC and prevented the formation of reticular proeutectoid ferrite and coarse pearlite in steel, then made the tempered troostite of heat-treated spring steel become fine and uniform. However, much BN and boron carbide formed along prior austenite grain boundaries in spring steel containing 43 ppm boron and was retained after quenching and tempering, leading to the decrease of ductility and fatigue life of spring steel. Therefore, 23 ppm boron was the best content for increasing hot ductility and ductility at room temperature of spring steel, and improved its tensile strength and elastic sag resistance, finally, the fatigue life increased from 5.3 × 107 cycles to 8.2 × 107 cycles.
Research on Measuring Method of Conveying Capacity of Mining Belt Conveyor
Authors: Zhu Shengqiang , Zhang Shaobin
Published: February 2023

This paper introduces the background of the use of mining belt conveyors, and summarizes the current research status and application of the commonly used methods for measuring the conveying capacity of belt conveyors. The development trend of belt conveyor conveying capacity measurement method in the future is put forward, that is, high measurement accuracy, strong anti-interference, and strong adaptability. At the same time, it is pointed out that a variety of combined measurement methods or non-contact measurement methods will become the belt conveyor conveying capacity. The mainstream method of measurement, the future development needs to be accompanied by the common development of artificial intelligence, image processing, machinery, electronics and other technologies.
Second Order Model with Composite Quantile Regression
Authors: Cheng Hao
Published: February 2023

In many fields, comprehensive evaluation is a very important topic. Both second order model and its modified one with quantile regression have been widely used in evaluation. Although quantile-type second order model has abilities in capturing a complete picture of different variables’ relations at different quantile levels. Sometimes we find it complex to summarize the conclusions of all quantile levels. Therefore, we propose a new second order model with composite quantile regression, which has the advantage of obtaining a whole evaluation result based on all quantile levels. More specifically, one of our paper’s main contributions is to develop a comprehensive evaluation model based on the classical second order model, quantile regression and composite quantile regression. What’s more, we introduce a modified partial least square estimation algorithm under the well-known partial least squares framework. The new algorithm has the ability in estimating both path and loading coefficients reflecting the relationships among manifest variables and latent variables at all quantile levels.
Optimal Design on Pogo Stick in Multipurpose Measurement System of Aircraft’s Barycenter
Authors: Zhao Wenhui , Yang Yuhao , Sun Chaojian , Zheng Peng
Published: February 2023

The pogo stick is the main bearing part of the multipurpose measurement system for aircraft’s weight and barycenter. Its quality directly affects the stiffness and dynamic characteristics of the measurement system. The measurement and calculation method of large aircraft barycenter was designed based on the moment equilibrium principle. The core load-bearing component pogo stick was improved by adding a 3D force sensor. The structural strength of pogo stick was analyzed by finite element method, and its structure was optimized by geometric optimization method. The results show that compared with traditional measurement method of Z-direction force, this method can measure the 3D force and improve the measurement accuracy. The structural strength, distortion and geometry of models structural was optimal according to the simulation. The influence degree of each design variable on model’s distortion was found by geometry optimization.
Design and Analysis of a Sloshing Liquid Damping Device with Elastic Baffle Vibrator
Authors: Chang Peiran , Xu Xun , Huang Zijuan , Li Guojun
Published: February 2023

Sloshing liquid damping technology is a typical passive damping technology, which has many advantages in application. To improve the sloshing intensity of liquid, it is necessary to install internal components to increase damping of liquid. Elastic materials, especially rubber materials, are widely used as internal components of the deep-water damper, which would interact well with damping liquid. In this paper, a damping device combining elastic material with sloshing liquid damper is adopted, and a new-type elastic baffle oscillator sloshing liquid damper is proposed by using the lag function of the spring device to transmit the force. The damping mechanism of the structure and the core factors affecting the damping performance are studied. The numerical simulation results show that by adjusting the stiffness of the internal spring, the phase difference between the structural displacement and the acting force of the internal spring on the structure can be changed in a large range. Under the working condition of this paper, when the elastic coefficient is 2000 N·m−1, the phase difference is close to π/2, and the amplitude of the last wave trough of the structural displacement is only 0.5% of the initial amplitude, which indicates that the damping performance is excellent.
Application of Frequency Domain Analysis Method in Vibration Analysis and Fault Diagnosis of Oil Transfer Pump Unit
Authors: Liu Baoxia , Xu Chenchen , Li Gang , Yang Yang , Dai Lei
Published: February 2023

The frequency domain analysis method was used to analyze the changes of the vertical spectrum of the non-driving end, the vertical spectrum of the driving end, the horizontal spectrum of the non-driving end and the horizontal spectrum of the driving end of the pump unit under different operating conditions. And the relationship between the vibration value of the motor and the temperature was summarized. The results show that the motor vibration signal components are mainly fundamental frequency and second harmonic, and there are third harmonic components; The motor vibration value increases with the increase of bearing bush temperature and winding temperature. The reason for the failure of the pump unit is that the motor heat is too large, which leads to the high temperature of the motor bearing bush and winding, and the rotor appears bending and expanding deformation, which leads to the increase of the vibration value of the motor. The results show that the frequency domain analysis method has a good application effect in vibration analysis and fault diagnosis of oil transfer pump unit.
Ultrasonic Vibration Theory and Its Application in Reducing Springback for Multi-point Forming
Authors: Li Xinqi , Hu Shicheng
Published: February 2023

As recently researches show that many fields for three-dimensional surfaces producing, such as aircraft manufacturing, shipbuilding, vehicle body, pressure vessel formation, sheet forming processes are commonly used. As the most usually sheet forming way, stamping springback is also an unavoidable phenomenon. In Multi Point Forming, the springback with ultrasonic forming method can evidently be reduced. In this paper, the mechanism of reducing the springback by the ultrasonic vibration forming method is mainly discussed. Through the numerical simulation software ANSYS/ABAQUS and the ultrasonic vibration forming tests of typical samples, ultrasonic vibration’s effect on the reducing of springback is studied. The springback obtained by theoretical derivation and numerical simulation is consistent with the experimental results.
A Fast Way to Measure the Range of a Fuel Cell Vehicle
Authors: Ting Guo , zhijun Wang , Guozhuo Wang , Wushiyu  , Wuzhen  , Rongliang Liang , Zhenyu Nie , Wangfang
Published: February 2023

This paper studies the current situation of energy management and driving range of fuel cell vehicles, and establishes a corresponding test and evaluation method for driving range. First of all, the situation of the fuel cell vehicle mileage at home and abroad standards is analyzed, the energy change law of the fuel cell and the power battery under the cycle working conditions is studied, and the rapid test and evaluation method of the driving range of the full-power model and the rapid test and evaluation method of the mileage of the electro-electric hybrid are established for different energy mixing states. The established test analysis method plays an important role in the rapid development of fuel cell vehicles.
Integration of Rapid Prototyping Platform for Motor Control System into VeriStand Environment
Authors: Jiu Yuanwei , Zhang Han
Published: February 2023

During the design process of the motor control algorithm, the control parameters need to be constantly adjusted and the algorithm iteration process is complicated. This paper presents a rapid prototyping platform for motor control system with VeriStand environment integrated. The model real-time simulation layer is developed based on VeriStand, LabVIEW, and Simulink, which constitutes the virtual controller of the rapid prototyping platform. Combined with the human-computer interaction layer and data interaction layer based on the embedded system, the rapid prototyping platform can evaluate the performance of the control algorithm before the actual controller is completed, effectively shortening the development period. This rapid prototyping platform has the advantage of high real-time performance, which is convenient for users to design and simulate, and can be widely used in various motor control systems.
Research on Displacement Measurement and Self-detecting Circuit Based on LVDT
Authors: Zhang Xiaomin , Liu Huan , Che Mingshuo , Geng Zhenhua , Jiu Yuanwei
Published: February 2023

A Liner Variable Differential Transformer (LVDT) measuring system and self-detecting circuit are proposed for micro-displacement measurement, which can detect the displacement of LVDT and monitor the fault signals simultaneously. The circuit is composed of a focusing mechanism, a displacement measurement module, a correction module, a monitoring module, an AD conversion module, a drive module, a control module and a power conversion module. Due to the requirements of high reliability and long life of space remote sensing system, as well as the radiation influence in space, LVDT measurement and control data need to be monitored and validated. The displacement signal output of LVDT is an important signal quantity for fault detection and closed-loop control of the system. By analysing the displacement signal and drive output signal of LVDT, fault modes such as mechanism stuck-up and mechanism disconnection are detected. Aiming at the limitation of current detection methods, this paper proposes a method of detecting LVDT signal. Circuit protection is added to the circuit to improve the reliability of the circuit. The linearity and fault detection ability of the circuit are tested and analysed.
Calibration sources for the LEGEND-200 experiment
Authors: Baudis L. , Benato G. , Bond E.M. , Chiu P.J. , Elliott S.R. , Massarczyk R. , Meijer S.J. , Müller Y.
Published: February 2023

In the search for a monochromatic peak as the signature of
neutrinoless double beta decay an excellent energy resolution and an
ultra-low background around the Q-value of the decay are
essential. The LEGEND-200 experiment performs such a search with
high-purity germanium detectors enriched in 76Ge immersed in
liquid argon. To determine and monitor the stability of the energy
scale and resolution of the germanium diodes, custom-made,
low-neutron emission 228Th sources are regularly deployed in
the vicinity of the crystals. Here we describe the production
process of the 17 sources available for installation in the
experiment, the measurements of their alpha- and gamma- activities,
as well as the determination of the neutron emission rates with a
low-background LiI(Eu) detector operated deep underground. With a
flux of
( 4.27 ± 0.60stat ± 0.92syst) ×
10-4 n / (kBq·s), approximately one order of
magnitude below that of commercial sources, the neutron-induced
background rate, mainly from the activation of 76Ge, is
negligible compared to other background sources in LEGEND-200.
Matrix Jacobi biorthogonal polynomials via Riemann–Hilbert problem
Authors: Branquinho Amílcar , Foulquié-Moreno Ana , Fradi Assil , Mañas Manuel
Published: February 2023

We consider matrix orthogonal polynomials related to Jacobi type matrices of weights that can be defined in terms of a given matrix Pearson equation. Stating a Riemann–Hilbert problem we can derive first and second order differential-difference relations that these matrix orthogonal polynomials and the second kind functions associated to them verify. For the corresponding matrix recurrence coefficients, non-Abelian extensions of a family of discrete Painlevé d-P

I
V

_{IV}

equations are obtained for the three term recurrence relation coefficients.
A topological characterisation of the Kashiwara–Vergne groups
Authors: Dancso Zsuzsanna , Halacheva Iva , Robertson Marcy
Published: February 2023

In [Math. Ann. 367 (2017), pp. 1517–1586] Bar-Natan and the first author show that solutions to the Kashiwara–Vergne equations are in bijection with certain knot invariants: homomorphic expansions of welded foams. Welded foams are a class of knotted tubes in

R

4

\mathbb {R}^4

, which can be finitely presented algebraically as a circuit algebra, or equivalently, a wheeled prop. In this paper we describe the Kashiwara-Vergne groups

K
V

\mathsf {KV}

and

K
R
V

\mathsf {KRV}

—the symmetry groups of Kashiwara-Vergne solutions—as automorphisms of the completed circuit algebras of welded foams, and their associated graded circuit algebras of arrow diagrams, respectively. Finally, we provide a description of the graded Grothendieck-Teichmüller group

G
R
T

1

\mathsf {GRT}_1

as automorphisms of arrow diagrams.
Transcriptome analysis of brassinolide under low temperature stress in winter wheat
Authors: Ding Meiyun , Wang Luyao , Sun Yuting , Zhang Junbao , Chen Yushu , Wang Xuesong , Liu Lijie
Published: February 2023

Low temperatures are the main abiotic factor affecting wheat growth. Brassinolide is a novel plant hormone that can improve the cold resistance of plants; however, the molecular mechanism of brassinolide in winter wheat at low temperatures remains unclear. In this study, winter wheat Dongnong dongmai 1 was sprayed with 0.01, 0.1, or 1.0 mg·L–1 brassinolide (BR) at the three-leaf stage, and tillering nodes were sampled at different temperatures (5, –10 and –25 °C), and then physiological indexes were determined and the transcriptome was sequenced. The results showed that the optimum concentration of brassinolide for cold resistance is 0.1 mg·L–1. A total of 15 302 (8198 upregulated and 7104 downregulated) differentially expressed genes (DEGs) were identified in the B1 vs D1 comparison (B1 represents 5 °C 0.1 mg·L–1 BR treatment, D1 represents 5 °C control); 3386 (1930 upregulated and 1456 downregulated) differentially expressed genes (DEGs) were identified in the B2 vs D2 comparison (B2 represents –10 °C 0.1 mg·L–1 BR treatment, D2 represents –10 °C control); and 2684 (2102 upregulated and 582 downregulated) differentially expressed genes (DEGs) were identified in the B3 vs D3 comparison (B3 represents –25 °C 0.1 mg·L–1 BR treatment, D3 represents –25 °C control). Further studies showed that these DEGs were mainly involved in carbon fixation in photosynthetic organs, photosynthesis and plant–pathogen interactions, all of which were related to stress and energy metabolism. This indicates that brassinolide can produce substances that improve cold resistance in wheat seedlings. This study provides a theoretical basis for further research on the improvement of cold resistance in winter wheat by brassinolide.