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Numerical Simulation of Water Entry of Wedges in Waves Using A CIPBased Model

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China Ocean Engineering 2021年第1期35卷 48-60页

作者： HU Zi-jun ZHAO xi-zeng LI Meng-yu ZHAO xin YAO Wen-wei SHAO Jie Zhejiang Institute of Hydraulic and Estuary Hangzhou 310020China Ocean College Zhejiang UniversityZhoushan 316021China

In this study,the water entry of wedges in regular waves is numerically investigated by a two-dimensional in-house numerical *** numerical model based on the viscous Navier−Stokes(N−S)equations employs a high-order different method—the constrained interpolation profile(CIP)method to discretize the convection term.A Volume of Fluid(VOF)-type method,the tangent of hyperbola for interface capturing/slope weighting(THINC/SW)is employed to capture the free surface/interface,and an immersed boundary method is adopted to treat the motion of *** momentum source function derived from the Boussinesq equation is applied as an internal wavemaker to generate regular *** accuracy of the numerical model is validated in comparison with experimental results in the *** results of water entry in waves are provided in terms of the impact force of wedge,velocity and pressure distributions of *** attention is paid to the effects of wave parameters and the position of wedge impacting the water *** is found that the existence of waves significantly influences the velocity and pressure field of fluid and impact force on the wedges.

关键词： Water entry water wave wedge internal wave maker CIP method VOF method

Observation of mechanical bound states in the continuum in an optomechanical microresonator

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Light(Science & Applications) 2022年第12期11卷 2931-2938页

作者： yue yu xiang xi xiankai Sun Department of Electronic Engineering The Chinese University of Hong KongShatinNew TerritoriesHong Kong SARChina

Bound states in the continuum(BICs)are a type of waves that are perfectly confined in the continuous spectrum of radiating waves without interaction with ***,we fabricated,with CMOS-compatible processes on a silicon chip,a wheel-shaped optomechanical microresonator,in which we experimentally observed the BIC in the micromechanical *** BIC results from destructive interference between two dissipative mechanical modes of the microresonator under broken azimuthal *** BICs can be obtained from devices with large and robust supporting structures with variable sizes,which substantially reduces fabrication difficulty and allows for versatile application *** results open a new way of phonon trapping in micromechanical structures with dissipation channels,and produce long phonon lifetimes that are desired in many mechanical applications such as mechanical oscillators,sensors,and quantum information processors.

关键词： phonon continuum states

Enhanced oxidation resistance of low-carbon MgO-C refractories with ternary carbides:a review

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Journal of Iron and Steel Research International 2022年第7期29卷 1052-1062页

作者： Chao yu Bo Dong yu-feng Chen Bei-yue Ma jun Ding Cheng-ji Deng Hong-xi Zhu Jing-hui Di The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

The demand for low-carbon MgO–C refractories is ever growing to meet the development of advanced steelmaking technologies and efficient energy ***,to improve the oxidation resistance and inhibit the weakness of low-carbon MgO–C refractories,antioxidants are *** application of ternary carbides that focused on improving the oxidation performance of MgO–C refractories has been explored,and the ternary carbides including Al_(4)O_(4)C,Al8B_(4)C_(7),Al_(4)SiC_(4),Ti_(2)AlC,Ti_(3)AlC_(2),and Ti_(3)SiC_(2)have been proved *** crystal structure,physical properties,oxidation behavior,and synthesis of these ternary carbides were summarized,and their oxidation mechanism in assisting antioxidation of MgO–C refractories was *** addition,the potential aspects related to the usage and development of ternary carbides in low-carbon MgO–C refractories were proposed.

关键词： Low-carbon MgO–C refractory Ternary carbide MAX phase Oxidation mechanism Oxidation resistance

The effect of COVID-19 vaccines on sperm parameters: a systematic review and meta-analysis

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Asian Journal of Andrology 2023年第4期25卷 468-473页

作者： yu-Cheng Ma Chao Cheng Chi yuan Li-yuan xiang jun Wen xi Jin Department of Urology Institute of Urology(Laboratory of Reconstructive Urology)West China HospitalSichuan UniversityChengdu 610000China

Published data were gathered for a meta-analysis to determine the difference in sperm parameters before and after administration of different types of coronavirus disease 2019(COVID-19)vaccines,because the reproductive toxicity of COVID-19 vaccines has not yet been evaluated in clinical trials and COVID-19 has been associated with decreases in sperm *** preferred procedures for systematic reviews and meta-analyses were followed in the conduct and reporting of this *** average sperm parameters of all sperm donors’multiple sperm donations were compared before and after receiving various COVID-19 *** volume,total sperm motility,total sperm count,morphological change,and sperm concentration were the primary outcome *** compiled and analyzed the results of six studies on total sperm motility,six studies on semen volume,six studies on sperm concentration,two studies on morphological change,and two studies on total sperm *** comparisons with patients who had and had not been vaccinated were only reported in one of the included *** different types of COVID-19 vaccine injections were compared,no discernible differences in parameters were *** to the available data,the parameters of semen are unaffected by inactivated or messenger RNA(mRNA)COVID-19 *** support these findings,additional prospectively designed research is required.

关键词： COVID-19 mRNA vaccine sperm parameters sperm quality vaccine safety

Potential use of a dried saliva spot(DSS)in therapeutic drug monitoring and disease diagnosis

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Journal of Pharmaceutical Analysis 2022年第6期12卷 815-823页

作者： yu Han xi-Ling Li Minghui Zhang Jing Wang Su Zeng jun Zhe Min Key Laboratory of Natural Medicines of the Changbai Mountain Ministry of EducationDepartment of Pharmaceutical AnalysisCollege of PharmacyYanbian UniversityYanjiJilin133002China Institute of Drug Metabolism and Pharmaceutical Analysis Zhejiang Province Key Laboratory of Anti-Cancer Drug ResearchCollege of Pharmaceutical SciencesZhejiang UniversityHangzhou310058China

In recent years,scientific researchers have increasingly become interested in noninvasive sampling methods for therapeutic drug monitoring and disease *** a result,dried saliva spot(DSS),which is a sampling technique for collecting dried saliva samples,has been widely used as an alternative matrix to serum for the detection of target *** the DSS method with a highly sensitive detection instrument improves the efficiency of the preparation and analysis of biological ***,dried blood spots,dried plasma spots,and dried matrix spots,which are similar to those of the DSS method,are *** with alternative biological fluids used in dried spot methods,including serum,tears,urine,and plasma,saliva has the advantage of convenience in terms of sample collection from children or persons with *** review aims to provide integral strategies and guidelines for dried spot methods to analyze biological samples by illustrating several dried spot ***,we summarize recent advancements in DSS methods from june 2014 to March 2021 and discuss the advantages and disadvantages of the key aspects of this method,including sample preparation and method ***,we outline the challenges and prospects of such methods in practical applications.

关键词： Human saliva Dried saliva spot Therapeutic drug monitoring Disease diagnosis

Dynamical signatures of the one-dimensional deconfined quantum critical point

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Chinese Physics B 2022年第5期31卷 73-82页

作者： Ning xi Rong yu Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of ChinaBeijing 100872China

We study the critical scaling and dynamical signatures of fractionalized excitations at two different deconfined quantum critical points(DQCPs)in an S=1/2 spin chain using the time evolution of infinite matrix product *** scaling of the correlation functions and the dispersion of the conserved current correlations explicitly show the emergence of enhanced continuous symmetries at these *** dynamical structure factors in several different channels reveal the development of deconfined fractionalized excitations at the ***,we find an effective spin-charge separation at the DQCP between the ferromagnetic(FM)and valence bond solid(VBS)phases,and identify two continua associated with different types of fractionalized excitations at the DQCP between the X-direction and Z-direction FM *** findings not only provide direct evidence for the DQCP in one dimension but also shed light on exploring the DQCP in higher dimensions.

关键词： one-dimensional antiferromagnetism spin frustration deconfined quantum critical point spin dynamics infinite time-evolving block decimation

What is the right way to quench star formation in semi-analytic models of galaxy formation?

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Research in Astronomy and Astrophysics 2017年第2期17卷 7-16页

作者： yu Luo xi Kang Purple Mountain Observatory the Partner Group of MPI für Astronomie Graduate School University of the Chinese Academy of Sciences

Semi-analytic models of galaxy formation are powerful tools to study the evolution of a galaxy population in a cosmological context. However, most models overpredict the number of low- mass galaxies at high redshifts and the colors of model galaxies are not right in the sense that low-mass satellite galaxies are too red and centrals are too blue. The recent version of the L-Galaxies model by Henriques et al. （H15） is a step forward to solve these problems by reproducing the evolution of stellar mass function and the overall fraction of red galaxies. In this paper we compare the two model predictions of L-Galaxies （the other is Guo et al., G13） to SDSS data in detail. We find that in the H15 model the red fraction of central galaxies now agrees with the data due to their implementation of strong AGN feedback, but the stellar mass of centrals in massive halos is now slightly lower than what is indicated by the data. For satellite galaxies, the red fraction of low-mass galaxies （log M./M~ 〈 10） also agrees with the data, but the color of massive satellites （10 〈 logM,/M~ 〈 11） is slightly bluer. The correct color of centrals and the bluer color of massive satellites indicate that quenching in massive satellites is not strong enough. We also find that there are too many red spirals and less bulge-dominated galaxies in both H15 and G13 models. Our results suggest that additional mechanisms, such as more minor mergers or disk instability, are needed to slightly increase the stellar mass of the central galaxy in massive galaxies, mainly in the bulge component, and bulge dominated galaxies will be quenched not only by minor mergers, but also by some other mechanisms.

关键词： galaxies: evolution -- galaxies: formation- galaxies: star formation

Modeling of laser adjustment for large diameter tubes using robotic kinematic theories

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Advances in Manufacturing 2018年第4期6卷 401-408页

作者： Pin Li jun-Tong xi School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 People's Republic of China School of Mechanical Engineering Jiangsu University Zhenjiang 212013 Jiangsu Province People's Republic of China

Laser adjustment is a new technique that employs laser forming processes to align components along specific directions. To develop a laser adjustment solution with a minimal number of bends, herein, a new modeling and calculation method that uses robotic kinematic theories is introduced. A numerical example and the corresponding laser adjustment solution are presented. The simulation results suggest that a straight tube with a flange connector can be adjusted to match the corresponding connector with three bends. Finally, the simulation results were verified using experiments. The maximum deviation was approximately 0.4 mm and the deviation of the flange connector was smaller, showing that a good adjustment quality could be achieved using the specific adjustment solution.

关键词： Laser adjustment Large diameter tube Robotic kinematics theories Production of exponential formula

Hierarchically porous Beta/SBA-16 with different silica-alumina ratios and the hydrodesulfurization performances of DBT and 4,6-DMDBT

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Petroleum Science 2022年第1期19卷 375-386页

作者： Jin-Lin Mei yu Shi Cheng-Kun xiao Ao-Cheng Wang Ai-jun Duan xi-Long Wang State Key Laboratory of Heavy Oil Processing China University of Petroleum(Beijing)Beijing 102249PR China

Hierarchically porous Beta/SBA-16(BS)composite materials,combining the characteristics of the acidity from the Beta zeolite and the three-dimensional structure from SBA-16,were synthesized successfully through a two-step in-situ assembly hydrothermal crystallization method.A series of Ni Mo catalysts supported on BS with different silica-alumina ratios were *** supports and the corresponding catalysts were characterized by XRD,N_(2) physisorption,^(27)Al MAS NMR,TEM,pyridine-FTIR,Raman,XPS and *** activities of series catalysts were evaluated by the hydrodesulfurization(HDS)performances of dibenzothiophene(DBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT).It was found that the Beta crystallites were embedded into SBA-16 through silanols accompanied by dealumination on the T3-T9 sites of Beta *** Mo/BS-3 with a silica-alumina ratio of 100 exhibited the highest DBT and 4,6-DMDBT HDS activities at the WHSV value of 10 h^(-1),with the conversions of 95.9%and 86.9%respectively,due to the synergistic effects of the suitable specific surface areas,the relatively large pore size,appropriate acidity,the relatively high sulfidation degree,moderate dispersity and good stacking degree of Mo S;active phases.

关键词： Beta/SBA-16 Dibenzothiophene 4,6-Dimethyldibenzothiophene Hydrodesulfurization