bluuebunny/crossref_metadata_2025 huggingface dataset:
Desflurane anesthesia shifts the circadian rhythm phase depending on the time of day of anesthesia
Authors: Imai Ryo , Makino Hiroshi , Katoh Takasumi , Kimura Tetsuro , Kurita Tadayoshi , Hokamura Kazuya , Umemura Kazuo , Nakajima Yoshiki
Published: October 2020

Desflurane is one of the most frequently used inhalational anesthetics in clinical practice. A circadian rhythm phase-shift after general anesthesia with sevoflurane or isoflurane has been reported in mice, but few studies have reported this effect with desflurane. In the present study, we examined the rest/activity rhythm of mice by counting the number of running wheel rotations, and we found that desflurane anesthesia caused a phase shift in the circadian rhythm that was dependent on the time of day of anesthesia. We also found that desflurane anesthesia altered the relative mRNA expression of four major clock genes (Per2, Bmal, Clock, and Cry1) in the suprachiasmatic nucleus (SCN). These results are important for elucidating the effects of desflurane on the SCN, which is the master clock for the mammalian circadian rhythm. Further studies on the relationship between anesthesia and circadian rhythm may lead to the prevention and treatment of postoperative complications related to circadian rhythms.
Iron catalyzed stereoselective alkene synthesis: a sustainable pathway
Authors: Duan Xin-Fang
Published: October 2020

Replacing expensive or toxic transition metals with iron has become an important trend. This article summarises the recent progresses of a wide range of Fe-catalyzed reactions for accessing various stereodefined alkenes.
Ultrastable radical-doped coordination compounds with antimicrobial activity against antibiotic-resistant bacteria
Authors: Ke Hua , Hu Fen , Meng Lingyi , Chen Qi-Hua , Lai Qian-Sheng , Li Ze-Chen , Huang Ze-Long , Liao Jian-Zhen , Qiu Jian-Ding , Lu Can-Zhong
Published: October 2020

Radical-doped coordination compounds—generated as a result of lone pair–π interactions and having a long-lived charge-separated state—display photochromism and broad-spectrum antimicrobial activity, even against multi-drug-resistant bacteria.
Understanding the structural properties of p-xylylenebis(triphenylphosphonium) cation under different pH and anion conditions
Authors: Ling Irene , Sobolev Alexandre N. , Skelton Brian W. , Raston Colin L.
Published: October 2020

Cis- and trans-conformers of the p-xylylenebis(triphenylphosphonium) dication can be accommodated in crystalline solids, depending on the pH of the solution and the presence of auxiliary anions (including p-sulfonatocalix[4]arene) and cations.
Selective adsorption of monovalent cations in porous electrodes
Authors: Kiyohara Kenji , Yamamoto Yuji , Kawai Yusuke
Published: October 2020

Selective adsorption of hydrated ions in porous electrodes is controlled by the pore size and the applied voltage.
Correction: Localization in the SCAN meta-generalized gradient approximation functional leading to broken symmetry ground states for graphene and benzene
Authors: Zhang Yubo , Zhang Wenqing , Singh David J.
Published: October 2020

Correction for ‘Localization in the SCAN meta-generalized gradient approximation functional leading to broken symmetry ground states for graphene and benzene’ by Yubo Zhang et al., Phys. Chem. Chem. Phys., 2020, 22, 19585–19591, DOI: 10.1039/D0CP03567J.
Tuning Rh(ii)-catalysed cyclopropanation with tethered thioether ligands
Authors: Cressy Derek , Zavala Cristian , Abshire Anthony , Sheffield William , Darko Ampofo
Published: October 2020

Dirhodium(ii) paddlewheel complexes have high utility in diazo-mediated cyclopropanation reactions and ethyl diazoacetate is one of the most commonly used diazo compounds in this reaction.
Highly selective photo-hydroxylation of phenol using ultrathin NiFe-layered double hydroxide nanosheets under visible-light up to 550 nm
Authors: Wang Jikang , Xu Yanqi , Li Jiaxin , Ma Xiaodong , Xu Si-Min , Gao Rui , Zhao Yufei , Song Yu-Fei
Published: October 2020

Ultrathin NiFe-LDH nanosheets with abundant defects show a highly selective photo-driven Fenton hydroxylation reaction under visible-light irradiation even at a wavelength of 550 nm.
Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials
Authors: Carter Simon , Clough Robert , Fisher Andy , Gibson Bridget , Russell Ben , Waack Julia
Published: October 2020

This review covers advances in the analysis of advanced materials, metals, fuels and lubricants, nanostructures, ceramics, refractories, organic and inorganic chemicals, catalysts and nuclear materials by a range of techniques including X-ray, ICP, LIBS, mass spectrometry, synchrotron-based techniques, plus non-destructive and ablation surface techniques.
Study on the extraction, purification, partial chemical characterization and anti-alcohol liver injury activity of Mori Fructus polysaccharides
Authors: Chen Huaguo , Xiao Ruixi , Zhou Xin
Published: October 2020

Mori Fructus (MF) is a fruit rich in many nutrients.
Dynamics of the efficient cyclometalation of the undercoordinated organoplatinum complex [Pt(COD)(neoPh)]+ (neoPh = 2-methyl-2-phenylpropyl)
Authors: Neugebauer Michael , Schmitz Simon , Brünink Dana , Doltsinis Nikos L. , Klein Axel
Published: October 2020

The cyclometalation reaction of [Pt(COD)(κ1-neoPh)]+ (neoPh = 2-methyl-2-phenylpropyl) to [Pt(COD)(κ2-neoPh)] was studied experimentally and mechanistically using DFT and MD simulations.
Pd nanoparticles as a plasmonic material: synthesis, optical properties and applications
Authors: De Marchi Sarah , Núñez-Sánchez Sara , Bodelón Gustavo , Pérez-Juste Jorge , Pastoriza-Santos Isabel
Published: October 2020

Pd as an alternative material for nanoplasmonics.
DBU-promoted ring-opening reactions of multi-substituted donor–acceptor cyclopropanes: access to functionalized chalcones with a quaternary carbon group
Authors: Luo Naili , Liu Jiamin , Wang Shan , Wang Cunde
Published: October 2020

A strategy to synthesize highly stereoselective chalcones with alkylcyanoacetate subunits via DBU-promoted ring-opening reactions of multi-substituted D–A cyclopropanes has been developed without the requirement of a transition metal catalyst and extra solvent.
Programming electronic skin with diverse skin-like properties
Authors: Huang Jinjian , Liu Ye , Chi Xiang , Jiang Yungang , Xu Ziyan , Qu Guiwen , Zhao Yun , Li Zongan , Chen Canwen , Chen Guopu , Wu Xiuwen , Ren Jianan
Published: October 2020

Simulating the comprehensive functions of native skin—and not simply the perception of external physical stimuli—by electronic skin (e-skin) has gathered increasing attention in the development of wearable devices and human-interactive technology.
miR-371b-5p promotes cell proliferation, migration and invasion in non-small cell lung cancer via SCAI
Authors: Luo Xue , Zhang Xiaolei , Peng Jianming , Chen Yan , Zhao Wenhui , Jiang Xiuling , Su Landi , Xie Mingqi , Lin Bo
Published: October 2020

Objective: Multiple gene targets have been reported for treatment of non-small cell lung cancer (NSCLC), however, the accompanying genetic tolerance was reported increasingly. Therefore, it is important to find new biomarkers or therapeutic targets in treatment of NSCLC.

Methods: The expression levels of miR-371b-5p were detected by qRT-PCR in NSCLC tissues and cell lines. To evaluate the effect of miR-371b-5p on NSCLC progression, we first transfected the miR-371b-5p inhibitor for construction of the miR-371b-5p down-regulated cell model. Then the cell proliferation, migration, invasion and cell apoptosis were detected. In addition, the expression levels of adhesion factors were detected. The target gene of miR-371b-5p was identified by bioinformatics analysis, and rescue experiment was conducted to validate the effect of miR-371b-5p on proliferation, migration and invasion of NSCLC.

Results: Our findings revealed that the miR-371b-5p was overexpressed in NSCLC and could markedly promote the cell proliferation, migration and invasion. Expression levels of both intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were significantly down-regulated when treated by miR-371b-5p inhibitor. Moreover, dual-luciferase reporter assay showed that the miR-371b-5p targeted SCAI in regulation of cell proliferation, migration and invasion, and the expression of miR-371b-5p was negatively associated with SCAI in NSCLC tissues and cell lines. Rescue experiment revealed that the miR-371b-5p could rescue the effect of SCAI on cell proliferation, migration and invasion.

Conclusion: Our results suggest that the miR-371b-5p and SCAI may serve as novel prognostic biomarkers and therapeutic targets for NSCLC.
Scaled consensus for coupled harmonic oscillators via sampled position data
Authors: Yao Zhongsheng , Vong Seakweng
Published: October 2020

This study considers the scaled consensus problem of coupled harmonic oscillators with a directed network topology. A distributed control protocol with input delay and intermittent sampled position information only is proposed. To achieve consensus, a necessary and sufficient condition depending on communication width, input delay and sampling period is derived. Furthermore, to save energy and improve the efficiency of communication among the agents and their neighbours, the authors extend their argument to investigate an impulsive control protocol. Different from intermittent control, the scaled consensus under the impulsive control cannot be achieved if there is no input delay. Numerical simulations illustrate that appropriately chosen control gains can verify the theoretical results.
Real‐time extremum seeking controller for brushless DC hub motors in electric vehicles
Authors: Ramaraj Ramachandran , Dharmaraj Ganeshaperumal , Srinivasan Seshadhri , Balasubramanian Subathra , Periyasamy Muthuvel , Bekiroglu Korkut
Published: October 2020

This study presents an extremum seeking‐proportional–integral and derivative (ES‐PID) controller design for brushless direct current motors and its implementation in electric vehicles. The ES‐PID controller aims to simultaneously maintain a speed set‐point and reduce torque ripples in the presence of load‐torque disturbances. The proposed ES‐PID combines the simplicity of a PID controller with an extremum seeking approach, a model‐free optimisation approach, thereby resulting in an optimal controller that can be realised on simple hardware (with limited computing power and memory). In addition, a theoretical analysis of the proposed ES‐PID control scheme in terms of stability and convergence is also presented. Performance evaluation of the proposed ES‐PID controller using both simulations and hardware experiments are presented. The results clearly illustrate the ability of the controller to track speed set‐point and reduce torque ripples in the presence of load‐torque variations.
New phase‐changing soft open point and impacts on optimising unbalanced power distribution networks
Authors: Lou Chengwei , Yang Jin , Li Tianrui , Vega‐Fuentes Eduardo
Published: October 2020

Three‐phase unbalanced conditions in distribution networks are conventionally caused by load imbalance, asymmetrical fault conditions of transformers and impedances of three phases. The uneven integration of single‐phase distributed generation (DG) worsens the imbalance situation. These unbalanced conditions result in financial losses, inefficient utilisation of assets and security risks to the network infrastructure. In this study, a phase‐changing soft open point (PC‐SOP) is proposed as a new way of connecting soft open points (SOPs) to balance the power flows among three phases by controlling active power and reactive power. Then an operational strategy based on PC‐SOPs is presented for three‐phase four‐wire unbalanced systems. By optimising the regulation of SOPs, optimal energy storage systems dispatch and DG curtailment, the proposed strategy can reduce power losses and three‐phase imbalance. Second‐order cone programming (SOCP) relaxation is utilised to convert the original non‐convex and non‐linear model into an SOCP model which can be solved efficiently by commercial solvers. Case studies are conducted on a modified IEEE 34‐node three‐phase four‐wire system and the IEEE 123‐node test feeder to verify the effectiveness, efficiency and scalability of the proposed PC‐SOP concept and its operational strategy.
Linear state estimation and bad data detection for power systems with RTU and PMU measurements
Authors: Jovicic Aleksandar , Hug Gabriela
Published: October 2020

The reliability of state estimation is of vital importance for secure operation of a power system. The key features of any state estimator are its accuracy, robustness against bad data and the associated computational burden. In order to ensure full system observability and maximise accuracy, a state estimation algorithm needs to take into account all available measurements. A significant number of hybrid estimators that can process both the conventional measurements that have been used in transmission systems for decades, as well as the synchrophasor measurements, can be found in literature. However, these algorithms are predominantly non‐linear, thus requiring iterative solving procedures. In this study, a novel linear algorithm is proposed for state estimation including bad data detection of power systems that are monitored both by conventional and synchrophasor measurements. The proposed estimator is based on the linear weighted least square framework. As a result, the computational burden is rendered extremely low since there is no need for an iterative solving procedure, and standardised post‐processing tools for bad data detection can be used. To validate the accuracy and robustness of the proposed algorithm, an extensive number of test cases of different sizes are solved and the results are presented and discussed.
Impact assessment of high‐power domestic EV charging proliferation of a distribution network
Authors: Zaidi Arsalan , Sunderland Keith , Conlon Michael
Published: October 2020

Transport electrification is becoming the mainstream as a means to improve efficiency, performance, and sustainability of transportation systems. Electrical vehicles (EVs) can help to de‐carbonise the environment, but a downside is the technical issues presented to the low‐voltage distribution network. To quantify the stochastic nature of transport‐affected electrification, probabilistic load flow is employed. Monte Carlo‐based simulation is applied to accommodate the probabilistic uncertainties associated with variable EV charging patterns. This study considers high‐power charging (up to 11 kW) at the domestic level while monitoring power quality variations (voltage drop, voltage unbalance factor, voltage sag) standards. This work focuses on the Irish and UK, distribution system operator's–transmission system operator's perspectives, as it will help to identify the likely impacts due to high‐EV charger proliferation at household locations. The results indicate that if a 3.68 kW charger is used at the domestic level, it is possible for 40% of total household consumers to connect EVs directly to the distribution network without any power quality breaches. Furthermore, the proliferation of EV can be increased up to 100% if constrained to the start, and middle portions of the network (relative to the feeder substation transformer). For higher charger capacities (up to 11 kW), a bottleneck is presented regarding a resultant voltage unbalance factor.
Learning an adaptive model for extreme low‐light raw image processing
Authors: Fu Qingxu , Di Xiaoguang , Zhang Yu
Published: October 2020

Low‐light images suffer from severe noise and low illumination. In this work, the authors propose an adaptive low‐light raw image enhancement network to avoid parameter‐handcrafting in current deep learning models and to improve image quality. The proposed method can be divided into two sub‐models: brightness prediction and exposure shifting (ES). The former is designed to control the brightness of the resulting image by estimating a guideline exposure time . The latter learns to approximate an exposure‐shifting operator ES, converting a low‐light image with real exposure time to a noise‐free image with guideline exposure time . Additionally, structural similarity loss and image enhancement vector are introduced to promote image quality, and a new campus image data set (CID) for training the proposed model is proposed to overcome the limitations of the existing data sets. In quantitative tests, it is shown that the proposed method has the lowest noise level estimation score compared with the state‐of‐the‐art low‐light algorithms, suggesting a superior denoising performance. Furthermore, those tests illustrate that the proposed method is able to adaptively control the global image brightness according to the content of the image scene. Lastly, the potential application in video processing is briefly discussed.
Low‐profile and wideband gain enhanced Fabry–Perot cavity antenna using gradient PRS and AMC
Authors: Li Zhi‐peng , Peng Lin , Ma Jing , Shi Bin , Zhao Qi‐xiang , Jiang Xing , Li Si‐min
Published: October 2020

Low‐profile and wideband gain enhancement Fabry–Perot cavity antennas (FPCA) is proposed using gradient Partially Reflective Surface (PRS) and gradient Artificial Magnetic Conductor (AMC). A wideband source antenna is designed with a −10 dB impedance bandwidth of 58.1% (6.1–11.1 GHz). The PRS is constructed by a complementary frequency‐Selective Surfaces (FSS) with a square hole and four small patches in a unit, which realizes phase increasing with frequency. The PRS and the AMC are gradient alone x‐direction to achieve wideband phase compensation. While they are uniform in y‐direction to realize better gain enhancement. Compared with the source antenna, the gain enhancement of the proposed FPCA is about 4–7 dBi. Moreover, the simulated and measured 3‐dB gain bandwidths are 7.26–10.33 GHz (34.8%) and 6.8–10.8 GHz (46%), respectively. The gain enhanced bandwidth is about 52.3% (6.5–11.1 GHz). The impedance bandwidth is 6–11.1 GHz (59.65%). By using the gradient size AMC, the profile of the FPCA is reduced from 0.5λ0 to 0.2λ0, where λ0 is the wavelength of 8.5 GHz. The proposed FPCA has the characteristics of wide impedance bandwidth, wide 3‐dB gain bandwidth, wide gain enhanced bandwidth and low‐profile.
Multiple ray received power modelling for mmWave indoor and outdoor scenarios
Authors: Khawaja Wahab , Ozdemir Ozgur , Erden Fatih , Ozturk Ender , Guvenc Ismail
Published: October 2020

Millimetre‐wave (mmWave) frequency bands are expected to be used for future fifth generation networks due to the availability of a large unused spectrum. However, the attenuation at mmWave frequencies is high. To resolve this issue, the utilisation of high gain antennas and beamforming mechanisms are widely investigated in the literature. In this work, the authors considered mmWave end‐to‐end propagation modelled by individual ray sources and explored the effects of the number of rays in the model and radiation patterns of the deployed antennas on the received power. It is shown that taking the dominant two rays is sufficient to model the channel for outdoor open areas as opposed to the indoor corridor which needs five dominant rays to have a good fit for the measurement and simulation results. It is observed that the radiation pattern of the antenna affects the slope of the path loss. Multi‐path components increase the received power, thus, for indoor corridor scenarios, path loss according to the link distance is smaller for lower gain antennas due to increased reception of reflected components. For an outdoor open area, the slope of the path loss is found to be very close to that of the free space.
Low‐power up‐conversion folded CMOS mixer for 2–12 GHz ultra‐wideband applications
Authors: Chen Jun‐Da , Qian Jia‐bin
Published: October 2020

This study presents an ultra‐wideband up‐conversion mixer chip that operates within the frequency range of 2–12 GHz using TSMC 0.18 μm complementary metal oxide semiconductor (CMOS) technology. The architecture is based on that of a Gilbert cell mixer. The design of the transconductance stage is based on an inverting amplifier. Two series resonant inductors are used to increase the conversion gain of the mixer, and a transformer that consists of two self‐made inductors reduces the spatial requirement of the chip. This up‐mixer achieves a 12.48 dB conversion gain and features an excellent gain flatness value of ±1.2 dB. The local oscillator (LO)‐to‐radio‐frequency isolation is 44–20 dB, the input third‐order intercept point (IIP3) is −6.8 to −8 dBm and the DC power consumption is 5.084 mW for a supply voltage of 1 V. The total size of the chip for the up‐mixer is 1.2 × 1.2 mm2, including the pad frames.
Wide‐band polarisation‐independent metasurface‐based carpet cloak
Authors: Salami Pooria , Yousefi Leila
Published: October 2020

Although the ability of metasurfaces to control electromagnetic wavefronts has made it possible to design ultrathin carpet cloaks, the narrow operation bandwidth limits the performance of these cloaks. Here, the authors propose a new method to enhance operating bandwidth of metasurface‐based carpet cloaks. The proposed cloak consists of super‐cells providing appropriate phase shift to incident wave over a wide and continuous range of frequencies. Using the proposed method, a polarisation‐independent wide‐band single‐layer carpet cloak is designed and fabricated. The performance of the proposed technique is verified using both numerical and experimental data. Experimental results show that the cloak operates well at all frequencies in the range of 9–10 GHz. The proposed method can be used for designing single‐layer wide‐band metasurface‐based cloaks and illusion coatings at different frequency regimes.
Performance prediction and experimental study of variable displacement vane oil pump
Authors: He Shang Hong , Liu Xiang , Xiao Shixuan , Liu Guangming , Cai Hao
Published: October 2020

In order to fully predict the performance of variable displacement vane oil pump (VDVP) during concept design phase， one‐dimensional simulation software AMESim is used to model the centralised parameters of VDVP. Several important performance indexes of VDVP are predicted, including the flow, pressure, torque and initial variable point, it is proved by the bench test that the simulation results have a good correlation with the test results. In addition, the effect of leakage on volumetric efficiency is studied, external leakage is smaller than internal leakage, and the higher the temperature, the larger the leakage. The force characteristics of VDVP are studied. Under extreme conditions, the maximum pressure of the internal chamber is about 15.9 bar, and the maximum forces of the stator and rotor are 1920 and 1653 N, respectively. The effect of temperature on the frictional power is studied. Under low‐temperature conditions, the viscous frictional power is much greater than the dry frictional power, while the high temperature is the opposite.
Pressure transformation ratio characteristics of kidney‐shaped holes variable four‐port hydraulic transformer
Authors: Zhou Lianquan , Liu Qiang , Zhang Chu , Bo Xiaonan
Published: October 2020

The kidney‐shaped holes variable four‐port hydraulic transformer of inlet and outlet equal flow is proposed, such as the theory, the flow of port A and port B is the same and equivalent to a hydraulic motor. The flow of ports O and T is the same, and the equivalent of a hydraulic pump. The A and B kidney‐shaped holes of the valve plate are the same. The O and T kidney‐shaped holes are the same. The transformer ratio can be changed by adjusting the control angle of the valve plate. The mathematic models of displacement, angular torque, and pressure transformation ratio about the four‐port hydraulic transformer are built. The derivative relationship between the pressure transformation ratio and flow of port B, recycling pressure difference, and viscosity is deduced, respectively. Based on it, the influence characteristics of the three factors on the pressure transformation ratio are obtained. The result of theoretical analysis and simulation shows that the increment in the flow of load circuits leads to a decrease in the pressure transformation ratio, while the decrease in viscosity and the increment in recycling pressure difference lead to an increase in the pressure transformation ratio.
Analysis of self‐locking factors of single wedge two‐way backstop
Authors: Niu Guangran , Wu Hao , Wang Danyang , Nie Zhenjin
Published: October 2020

In this study, the structural composition and working principle of the single wedge two‐way backstop are analysed, and the factors affecting the self‐locking of the single wedge two‐way backstop are explored. Two wedge shapes are established, the contact stress between the wedge and the outer casing is calculated by ANSYS and compared with the stress value calculated by Hertz theory, to verify the applicability of the finite element method.
Optimisation design and analysis of variable‐diameter pipe parameters for solid–liquid two‐phase abrasive flow processing
Authors: Li Junye , Wang Xinpeng , Hu Jinglei , Zhang Jingran , Shi Guangfeng , Zhao Weihong , Zhang Hongwei
Published: October 2020

To study the quality control technology and process specifications of solid–liquid two‐phase abrasive flow research and development, the fourth‐order variable diameter pipe is taken as the research object, and then the quality control method of abrasive flow polishing variable diameter pipe is established. Through the analysis of the abrasive flow of the fourth‐order variable‐diameter pipe, it is known that the surface texture of the variable‐diameter pipe becomes smoother and denser after the grinding flow, and the surface roughness Ra of the variable‐diameter pipe is reduced from the original 1.469 μm to after polishing 0.295 μm, the surface roughness is improved, and the ideal polishing quality is obtained. Under the experimental conditions, the optimal process parameters of solid–liquid two‐phase abrasive flow were obtained, and the regression model of surface roughness and process parameters was established, which provided technology for engineering application of solid–liquid two‐phase abrasive flow.
Integrated modelling and simulation method of a cargo door actuator
Authors: Xiaolu Wang , Danyang Wang , Hao Wu , Jian Yu , Peng Guo , Zhenjin Nie
Published: October 2020

An integrated Matlab model comprising of an electro‐mechanical actuator (EMA) model, load model and state model has been constructed to investigate the cargo door actuator motion control, operation and working states, of which, a Simulink® servomotor system model is adopted to mimic the EMA actuator, a SimMechanics® model is used to compute the actuator's load, a Stateflow® state transition model is employed to simulate the working process. The results indicated that the motion is well controlled, generated load force is valid, working states and their transition logics are reasonable. The simulation verified the effectiveness and easiness of the integrated modelling method.
Numerical simulation and analysis of excited rotary valve flow field with computational fluid dynamics
Authors: Yu‐ning Song , Guochao Zhao , Peng Fu
Published: October 2020

In order to study the fluid flow characteristics of the key components in the hydraulic excited rotary valve, then determine the area of vortex and negative pressure to find the weak link in the structure and analyse the performance of the valve. Simulate the flow field in the rotary valve by Fluent fluid analysis software and set different opening degrees under the same boundary conditions. Studies showed that the velocity at the exit junction of the fluid in the rotary valve and the vortex degree of pressure are large at the oil groove. When the opening degree is small, the negative pressure is large, the vortex is obvious. When the opening becomes large, the negative pressure and vortex are improved. The research provides a theoretical basis for the optimisation and improvement of the rotary valve.
Multiphase feedback processes in the Sy2 galaxy NGC 5643
Authors: García-Bernete I. , Alonso-Herrero A. , García-Burillo S. , Pereira-Santaella M. , García-Lorenzo B. , Carrera F. J. , Rigopoulou D. , Ramos Almeida C. , Villar Martín M. , González-Martín O. , Hicks E. K. S. , Labiano A. , Ricci C. , Mateos S.
Published: October 2020

We study the multiphase feedback processes in the central ∼3 kpc of the barred Seyfert 2 galaxy NGC 5643. We used observations of the cold molecular gas (ALMA CO(2−1) transition) and ionized gas (MUSE IFU optical emission lines). We studied different regions along the outflow zone, which extends out to ∼2.3 kpc in the same direction (east-west) as the radio jet, as well as nuclear and circumnuclear regions in the host galaxy disk. The CO(2−1) line profiles of regions in the outflow and spiral arms show two or more different velocity components: one associated with the host galaxy rotation, and the others with out- or inflowing material. In the outflow region, the [O III]λ5007 Å emission lines have two or more components: the narrow component traces rotation of the gas in the disk, and the others are related to the ionized outflow. The deprojected outflowing velocities of the cold molecular gas (median Vcentral ∼ 189 km s−1) are generally lower than those of the outflowing ionized gas, which reach deprojected velocities of up to 750 km s−1 close to the active galactic nucleus (AGN), and their spatial profiles follow those of the ionized phase. This suggests that the outflowing molecular gas in the galaxy disk is being entrained by the AGN wind. We derive molecular and ionized outflow masses of ∼5.2 × 107 M⊙ (αCOGalactic) and 8.5 × 104 M⊙ and molecular and ionized outflow mass rates of ∼51 M⊙ yr−1 (αCOGalactic) and 0.14 M⊙ yr−1, respectively. This means that the molecular phase dominates the outflow mass and outflow mass rate, while the kinetic power and momentum of the outflow are similar in both phases. However, the wind momentum loads (Ṗout/ṖAGN) for the molecular and ionized outflow phases are ∼27−5 (αCOGalactic and αCOULIRGs) and < 1, which suggests that the molecular phase is not momentum conserving, but the ionized phase most certainly is. The molecular gas content (Meast ∼ 1.5 × 107 M⊙; αCOGalactic) of the eastern spiral arm is approximately 50−70% of the content of the western one. We interpret this as destruction or clearing of the molecular gas produced by the AGN wind impacting in the eastern side of the host galaxy (negative feedback process). The increase in molecular phase momentum implies that part of the kinetic energy from the AGN wind is transmitted to the molecular outflow. This suggests that in Seyfert-like AGN such as NGC 5643, the radiative or quasar and the kinetic or radio AGN feedback modes coexist and may shape the host galaxies even at kiloparsec scales through both positive and (mild) negative feedback.
Infrared interferometric imaging of the compact dust disk around the AGB star HR3126 with the bipolar Toby Jug Nebula
Authors: Ohnaka K. , Schertl D. , Hofmann K.-H. , Weigelt G.
Published: October 2020

Aims. The asymptotic giant branch (AGB) star HR3126, associated with the arcminute-scale bipolar Toby Jug Nebula, provides a rare opportunity to study the emergence of bipolar structures at the end of the AGB phase. Our goal is to image the central region of HR3126 with high spatial resolution.

Methods. We carried out long-baseline interferometric observations with AMBER and GRAVITY (2–2.45 μm) at the Very Large Telescope Interferometer with spectral resolutions of 1500 and 4500, speckle interferometric observations with VLT/NACO (2.24 μm), and imaging with SPHERE-ZIMPOL (0.55 μm) and VISIR (7.9–19.5 μm).

Results. The images reconstructed in the continuum at 2.1–2.29 μm from the AMBER+GRAVITY data reveal the central star surrounded by an elliptical ring-like structure with a semimajor and semiminor axis of 5.3 and 3.5 mas, respectively. The ring is interpreted as the inner rim of an equatorial dust disk viewed from an inclination angle of ~50°, and its axis is approximately aligned with the arcminute-scale bipolar nebula. The disk is surprisingly compact, with an inner radius of a mere 3.5 R⋆ (2 au). Our 2-D radiative transfer modeling shows that an optically thick flared disk with silicate grains as large as ~4 μm can simultaneously reproduce the observed continuum images and the spectral energy distribution. The images reconstructed in the CO first overtone bands reveal elongated extended emission around the central star, suggesting the oblateness of the star’s atmosphere or the presence of a CO gas disk inside the dust cavity. The object is unresolved with SPHERE-ZIMPOL, NACO, and VISIR.

Conclusions. If the disk formed together with the bipolar nebula, the grain growth from sub-micron to a few microns should have taken place over the nebula’s dynamical age of ~3900 yrs. The non-detection of a companion in the reconstructed images implies that either its 2.2 μm brightness is more than ~30 times lower than that of the red giant or it might have been shredded due to binary interaction.
Effect of Coulomb diffusion of ions on the pulsational properties of DA white dwarfs
Authors: Althaus Leandro G. , Córsico Alejandro H. , De Gerónimo Francisco
Published: October 2020

Context. Element diffusion is a key physical process that substantially affects the superficial abundances, internal structure, pulsation properties, and evolution of white dwarfs.

Aims. We study the effect of Coulomb separation of ions on the cooling times of evolving white dwarfs, their chemical profiles, the Brunt–Väisälä (buoyancy) frequency, and the pulsational periods at the ZZ Ceti instability strip.

Methods. We followed the full evolution of white dwarf models in the range 0.5 − 1.3 M⊙ derived from their progenitor history on the basis of a time-dependent element diffusion scheme that incorporates the effect of gravitational settling of ions due to Coulomb interactions at high densities. We compared the results for the evolution and pulsation periods of ZZ Ceti stars with the case where this effect is neglected.

Results. We find that Coulomb sedimentation profoundly alters the chemical profiles of ultra-massive (M⋆ ≳ 1 M⊙) white dwarfs throughout their evolution, preventing helium from diffusing inward toward the core, and thus leading to much narrower chemical transition zones. As a result, significant changes in the g-mode pulsation periods as high as 15% are expected for ultra-massive ZZ Ceti stars. For lower mass white dwarfs, the effect of Coulomb separation is much less noticeable. It causes period changes in ZZ Ceti stars that are below the period changes that result from uncertainties in progenitor evolution, but larger than the typical uncertainties of the observed periods.

Conclusions. Coulomb diffusion of ions profoundly affects the diffusion flux in ultra-massive white dwarfs, driving the gravitational settling of ions with the same A/Z (mass to charge number). We show that it strongly alters the period spectrum of such white dwarfs, which should be taken into account in detailed asteroseismological analyses of ultra-massive ZZ Ceti stars.
Factors Affecting the Structural Behavior of FRP Wrapped Concrete Columns and Applications in Design
Authors: Huang Shijia
Published: October 2020

In this paper, the FRP wrapped concrete column is investigated. . According to the research results of Shan et al. (2020) [2], Li et al. (2006) [3], and Deb et al. (2010) [4], this paper analyzes the variables that need to be controlled in the design of columns from these three perspectives: the shape of the cross-section, fiber orientation and bonding between the concrete column and FRP confinement. Impact tests and compressive tests are performed on different specimen. The setting of different samples follows the principle of controlling variables. The results indicate that FRP-wrapped columns with a circular cross-section are better than that with square or rectangular columns and basalt FRP is the optimal FRP material for strengthening the concrete column under the impact. Fiber orientation and types of bonding layers have a great impact on the mechanical properties of FRP wrapped concrete columns.
Comparative study on connection performance of steel joints in the prefabricated steel reinforced concrete shear wall
Authors: Lin GAO , Xian XIAO , Kaixuan GUO , Kunxiong LIU
Published: October 2020

In order to respond to the call of the strategy to vigorously carry out the fabricated structure, a new lateral connection joint-prefabricated steel joint with grouting bolt sleeve, which is adopted in the prefabricated steel reinforced concrete shear wall structure. Through uniaxial tensile test and finite element analysis, the prefabricated steel joint is comprehensive analysed, to get the impact trend of the anchorage length, sleeve wall thickness, bolt diameter to the connection performance, to determine the practicability and reliability of the connection way, and to ensure connection performance in the prefabricated steel reinforced concrete shear wall structure system. With the comparative studies, we find that, the finite element analysis and test results have high fitting degree, and can be verificated each other; the bolt diameter, sleeve wall thickness and anchor length all have positive effect trend on the tensile properties of the joint, but the influence decreases; The bolt diameter should be more than 12mm, the sleeve wall thickness should be more than 5mm, and the anchorage length should be more than 70mm; the shear bond diameter can reduce the diameter, and can change the section setting to the ring setting; the comparative results can provide reliable data support for the prefabricated steel connection joint design.
Finite element analysis of reinforced concrete beams with openings in the abdomen and strengthened with steel sleeves based on ANSYS
Authors: Shen Yaohui , Lin Longbin , Feng Zhengwei
Published: October 2020

The finite element software ANSYS is used to calculate the ultimate bearing capacity of ordinary beam and circular hole beam, and the results are compared with the test values made by predecessors. The value of shear transfer coefficient between cracks of reinforced concrete beam with circular hole in the abdomen in ANSYS finite element simulation is summarized. The coefficient is used to simulate the circular hole beam strengthened by steel sleeve, and it is pointed out that the steel tube is used to reinforce the circular hole beam The effect of tube reinforcement on the bearing capacity of circular hole beam is not obvious.
Characteristics of Diatom Assemblages in Surface Sediments of the new Yongding River and Haihe River Estuaries, Tianjin
Authors: Fang Jing , Liu Yufei , Wang Tianjiao , Yan Xia , Shuo Yang , Zhang Liping
Published: October 2020

Diatom analysis was conducted on the surface sediments from the estuaries of the new Yongding River and Haihe River in Tianjin. The results showed that the main diatom assemblages in the new Yongding River was Navicula marina-Auliscus caelatus-Coscinodiscus hirosakiensis-Coscinodiscusoculus-iridis and Auliscus caelatus- Coscinodiscusoculus-iridis-Cyclotella meneghiniana-Cyclotella stylorum in the Haihe River. There was saprophilous taxa, Cyclotella meneghiniana, in both estuaries indicating that the two estuaries were polluted to a certain degree.
Relation between Asphalt, Asphalt Mortar Properties and HMA Performance
Authors: Li Yongzhen , Liang Hao , Jiang Feng , Xia Yu
Published: October 2020

The relationship among asphalt, mortar and mixture performance was analyzed by grey correlation method by means of asphalt rheological test and hot mix freeze-thaw split test in this paper. The results show that the rheological properties of asphalt as well as asphalt mortar are closely related to HMA performance. Rheological index has a good advantage in explaining HMA pavement diseases. Asphalt stiffness, cohesion, yield stress, rutting coefficient, multiple stress creep and recovery have a high correlation with the strength of the mixture; meanwhile, softening point, normal stress, interface bonding ability of asphalt mortar and volume index of mixture have a high correlation with the water stability of the mixture. In the evaluation of asphalt and asphalt mortar, methods such as stress creep recovery, stress scanning (yield stress, normal stress) and interface bond test should be further proposed and popularized.
A comparative study on the role of electro-conductive plastics electrode in direct current electroosmosis
Authors: Bai Wei , Jian Tao , Lin Rongbing , Luo Xiaoqian , Kong Lingwei
Published: October 2020

The electrode material is one of the critical factors affecting the electroosmosis efficiency. The electroosmotic test was conducted to compare the current, volume moisture content, and energy consumption of Electro-Conductive Plastics Electrode (ECPE) and metal electrode in the dispose of sludge. The results show that: the current decreases of ECPE is smaller than the metal electrode before 20h, and the difference value of moisture content between cathode and anode of ECPE is smaller when electroosmosis is stable. The energy consumption of ECPE is lower in the range of soil moisture content of 35% - 60%. The ECPE has a particular advantage in energy consumption and uniformity of soil moisture content, but has a disadvantage in residual moisture content as compared with the metal electrode.
Application of ANSYS Finite Element Analysis in Teaching of Mechanics of Materials
Authors: Feng Wang , Yurong MA , Yaqiong Jiang , Dan Li , Haifei Liao
Published: October 2020

The traditional classroom teaching of mechanics of materials focuses on the theoretical derivation of the formula, and the content is relatively boring. However, in the experimental class, the calculation formula of bending normal stress is simply verified, and other information other than deformation can not be given directly. In order to improve the effect of classroom teaching, ANSYS finite element analysis and pure bending experiment are combined and applied to the classroom teaching of material mechanics. The deformation and stress in the deformation problem of material mechanics are vividly displayed in the form of animation and cloud chart. Practice has proved that this teaching method can not only deepen students’ understanding of abstract mechanical concepts, but also stimulate students’ interest in learning and innovative thinking, which is conducive to the cultivation of engineering application-oriented talents.
Based on systems science methodology—— Research on the talent training system of hall three-dimensional structure
Authors: Yong-Chen  , Hua-Cheng Zhong , Qi-Xu
Published: October 2020

Draw lessons from the basic idea of system science methodology, based on the hall three dimensions structure theory construction of research personnel training problems, from the time dimension, logic knowledge and three dimension analysis of all aspects of talent cultivation system, clear the talent training theory support, and solve the problem of a series of contradictions in the process of talent training, further enriched and developed the theoretical system of talents cultivation.
Research on capacity configuration method of microgrid considering system cost
Authors: Hu Ning , Si Juncheng , Wang Yuanyuan , Wang Dehua , Liu Hanghang , Li Guanglei
Published: October 2020

Microgrid is a new type of power supply structure and will play an important role in ensuring power supply. Because of the high cost of micro grid construction, this is very necessary to determine the lowest capacity configuration and realize the best function configuration, which is an urgent problem in engineering construction. Therefore, this paper first establishes simulation analysis model, puts forward economic optimization model and constraints, and formulates system configuration scheme and construction cost. The results show that the method is feasible and effective. This scheme not only reduces the operation cost of the system, but also provides a reference for the construction of microgrid engineering.
Optimization research on hinge points of the grader’s working device based on ADAMS
Authors: le Gao , Penglong Hou , Junjie Duan
Published: October 2020

In order to study the hinge points load for grader’s working device, a multi-body dynamic model of the grader is established for analyzing the construction condition and obtain the load of each hinge point. The analysis method is verified by prototype test. Taking the force of the key cylinder as the optimization objective, the positions of all hinge points are optimized. The result show that the scheme reduces the maximum force of the key cylinder by 26.5%, which improve the stability of the grader.
Evaluation on water bursting risk of working faces near collapse column during the mining process
Authors: Xue Yang , Jingwu Huang , Hua Wang , Maoliang Liang , Wei Li , Huaqun Zhou , Yongjiang Zuo
Published: October 2020

Collapse column water bursting occurs from time to time in the coal mining process of North China Type Coalfield in China, which causes great economic loss and personal injury. Therefore, great attention must be paid to the harm of collapse column. 1301 working face and 1306 working face in the west wing of No.1 Mining District of Zhangji Coal Mine in Shanxian County are close to No.2 collapse column. Water bursting risk evaluation must be carried out before mining two working faces to ensure safety production. On the basis of fully analyzing the geological and hydrogeological conditions of the 3up coal seam in the west wing of No.1 Mining Area, the "Three Zones(caving zone, water conducted fracture zone and sagging zone) Theory of Coal Seam Roof", "Strata Movement Theory" and "Water Bursting Coefficient Theory" were used respectively to calculate and evaluate the water bursting risk of No.2 collapse column during the course of mining the 1301 working face and 1306 working face. The results show that: firstly, in the process of mining the 1301 working face, the maximum height of the water conducted fracture zone at the closest position of 1301 working face to No.2 collapse column would be 60.20 m, the water bursting coefficient on the boundary of water conducted fracture zone would be 0.066~0.072 MPa/m, and the water bursting risk of the No.2 collapse column would be smaller; secondly, in the process of mining the 1306 working face, the maximum height of the water conducted fracture zone at the closest position of 1306 working face to No.2 collapse column would be 60.91 m, the water bursting coefficient on the boundary of water conducted fracture zone would be 0.057~0.089 MPa/m, and the water burst risk of the No.2 collapse column would be small. By August 31, 2020, the 1301 working face had been safely mined more than 200 meters long(exceeding over 120 m of the closest position in 1301 working face to No.2 collapse column), and the water bursting did not happen in the working face. This paper can provide a reference for the water prevention and control of similar collapse columns in coal mines.
Study on early-warning System of Karst Tunnel Collapse
Authors: Yongyan YU , Dong MA , Chongtao Fu
Published: October 2020

During the construction of karst Tunnel, tunnel collapse often occurs. The establishment of early-warning system of tunnel collapse can effectively ensure the construction safety, but the research is insufficient. Based on the combination of theoretical analysis and engineering practice, this paper puts forward to early-warning system for karst tunnel collapse. (1) The evaluation index system of karst tunnel collapse is composed of anchor axial force, displacement, anchor pull-out force and steel arch stress. (2) The relationship between evaluation index and warning level is determined, and the early-warning system of tunnel collapse is established. (3) The model applied to Chong’anjiang tunnel collapse warning, and achieved good results.