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Shaking table test on a tunnel-group metro station in rock site under harmonic excitation

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Frontiers of Structural and Civil Engineering 2024年第9期18卷 1362-1377页

作者： Ruozhou LI Weiguo HE Xupeng YAO Qingfei LI Dingli ZHAng yong YUAN Department of Geotechnical Engineering Tongji UniversityShanghai 200092China China Railway Liuyuan Group Co. Ltd.Tianjin 300308China Key Laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China

A tunnel-group metro station built in rock site is composed of a group of *** tunnels and their interconnections can show inconsistent responses during an *** study investigates the dynamic responses of such a metro station in a rock site,by shaking table *** lining structures of each tunnel and surrounding rock are modeled based on the similitude law;foam concrete and gypsum are used to model the ground-structure system,keeping relative stiffness consistent with that of the prototype.A series of harmonic waves are employed as excitations,input along the transverse and longitudinal direction of the shaking *** discrepant responses caused by the structural irregularities are revealed by measurement of acceleration and strain of the *** characteristics are identified by the transfer function method in white noise *** test results show that the acceleration response and strain response of the structure are controlled by the *** particular,the acceleration amplification effect at the opening section of the station hall is more significant than that at the standard section under transverse excitation;the amplification effect of the structural opening is insignificant under longitudinal excitation.

关键词： metro station tunnel-group shaking table test harmonic excitation dynamic response

MXene: From synthesis to environment remediation

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Recent progress on impact induced reaction mechanism of reactive alloys

中国化学工程学报（英文版） 2023年第9期

作者： Ali Nikkhah Hasan Nikkhah Hadis langari Alireza Nouri Abdul Wahab Mohammad Ang Wei Lun ng law yong Rosiah Rohani Ebrahim Mahmoudi

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Defence Technology（防务技术） 2024年第7期37卷 69-95页

作者： Yansong Yang Chuanting Wang Yuanpei Meng Yue Ma Lei Guo Yuan He Zhichao Sun yong He School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094JiangsuChina

In recent years,in order to improve the destructive effectiveness of munitions,the use of new types of destructive elements is an important way to improve destructive *** a new type of reactive material,reactive alloy contains a large portion of reactive metal elements(Al,Mg,Ti,Zr,etc.),which breaks up under high-velocity impact conditions,generating a large number of high-temperature combustible fragments,which undergo a violent combustion reaction with *** with traditional metal polymers(Al-PTFE)and other reactive composites,it has higher density and strength,excellent mechanical properties and broader application ***,researchers have mainly investigated the impact energy release mechanism of reactive alloys through impact tests,and found that there are several important stages in the process of the material from fragmentation to reaction,i.e.,impact fragmentation of the material,rapid heating and combustion *** paper focuses on three problems that need to be solved in the impact-induced energy release process of reactive alloys,namely:the fragmentation mechanism and size distribution law of the fragments produced by the impact of the material on the target,the relationship between the transient temperatures and the size of the fragments,and the reaction temperatures and size thresholds of the fragments to undergo the chemical *** current status of the research of the above problems is reviewed,some potential directions to reveal the impact induced reaction mechanism of reactive alloy is discussed.

关键词： Reactive alloys Impact Fragmentation Mass and size distribution Shock temperature rise Adiabatic shear Combustion

A Study of 10 Rotating Radio Transients Using Parkes Radio Telescope

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Research in Astronomy and Astrophysics 2024年第4期24卷 114-123页

作者： Xinhui Ren Jingbo Wang Wenming Yan Jintao Xie Shuangqiang Wang Yirong Wen yong Xia Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Institute of Optoelectronic Technology Lishui UniversityLishui 323000China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China Research Center for Intelligent Computing Platforms Zhejiang LaboratoryHangzhou 311100China

Rotating Radio Transients(RRATs)are a relatively new subclass of pulsars that emit detectable radio bursts *** analyzed 10 RRATs observed using the Parkes telescope,with eight of these observed via the ultra-wide-bandwidth low-frequency(UWL)*** measured the burst rate and produced integrated profiles spanning multiple frequency bands for three *** also conducted a spectral analysis on both integrated pulses and individual pulses of three *** of their integrated pulses follow a simple power law,consistent with the known range of pulsar spectral *** average spectral indices of single pulses are-0.9,-1.2,and-1.0 respectively,which are within the known range of pulsar spectral ***,we find that the spreads of single-pulse spectral indices for these RRATs(ranging from-3.5 to+0.5)are narrower compared to what has been observed in other ***,the average spectral index and scatter of single pulses are both relatively *** the remaining five RRATs observed at the UWL receiver,we also provide the upper limits on fluence and flux *** addition,we obtain the timing solution of PSR *** analysis shows that PSRs J1919+1745,J1709-43,and J1649-4653 are potentially nulling pulsars or weak pulsars with sparse strong pulses.

关键词： (stars:)pulsars:general stars:neutron stars:individual(PSRs J1919+1745.1909+0641,0628+0909)

Effect of Menopausal Hormone Replacement Therapy on Cytokine Patterns in a Perimenopausal Mouse Model Established by the Ovarian Castration Method

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Chinese Journal of Biomedical Engineering(English Edition) 2024年第1期33卷 40-48页

作者： HE Bin-bin ZHAng Ju-shun WAng Jin-yong Longyan First Affiliated Hospital of Fujian Medical University Longyan Fujian 364000China

Objective: To investigate the effect of perimenopausal hormone replacement therapy(HRT) on cytokine patterns in a perimenopausal mouse model established by ovarian castration. Methods: The mice were divided into natural menopause group,ovariectomy group and HRT group, with 15 mice in each group, and the estrous cycle, estrous frequency and menopausal time of the mice were determined by vaginal cytology,and the estrous cycle, estrous frequency and menopausal time were compared among the three groups. The serum levels of estradiol(E2) and progesterone(P4) in each group were detected by double-antibody sandwich ELISA, and the levels of interferon gamma(IFN-γ), interleukin-2(IL-2), IL-4 and IL-10 in the spleen γ tissues of mice were detected by ELISA. Results: The time of menopause(53.07±3.99) d in the HRT group was between that of the natural menopause group(80.80±3.26) d and that of the ovariectomy group(16.27±4.35) d, with a statistically significant difference in the two-by-two comparison of the three groups(Png/L and P4(14.2 ±6.0) ng/L in the HRT therapy group are between those of the ovariectomy group and the natural menopause group, with statistically significant differences between the groups(P<0.05). The levels of IL-2(30.9±5.3) pg/ml, IL-4(9.4±1.6) pg/ml, IL-10(19.7±3.1) pg/ml, IFN-γ(22.0±3.7) pg/ml in the HRT group were all between those of natural menopause group and ovariectomy group. The Th1/Th2 ratio in the ovariectomy group was 7.55±1.57, higher than that in the natural menopause group(1.53±0.48) and HRT group(2.38 ±0.44), with statistically significant differences(P<0.05). Conclusion:Menopausal HRT can partially correct the imbalance of Th1/Th2 cytokines, which is able to provide an experimental basis for the regulation of menopause-related immune imbalance by HRT.

关键词： menopause hormone replacement therapy(HRT) ovariectomy mouse model cytokine pattern

Boson star superradiance

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 69-78页

作者： He-Yu Gao Paul M.Saffin Yi-Jie Wang Qi-Xin Xie Shuang-yong Zhou School of Physical Sciences University of Science and Technology of ChinaHefei 230026China School of Physics and Astronomy University of NottinghamUniversity ParkNottingham NG72RDUK Interdisciplinary Center for Theoretical Study University of Science and Technology of ChinaHefei 230026China Peng Huanwu Center for Fundamental Theory Hefei 230026China

Recently,it has been realized that in some systems internal space rotation can induce energy amplification for scattered waves,similar to rotation in real *** particularly,it has been shown that energy extraction is possible for a Q-ball,a stationary non-topological soliton that is coherently rotating in its field *** this paper,we generalize the analysis to the case of boson stars,and show that the same energy extraction mechanism still works for boson stars.

关键词： superradiance boson star field space rotation

Optimization of the co-closing law of guide vanes and blades for bulb turbines based on CFD

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Journal of Hydrodynamics 2024年第2期36卷 363-377页

作者： Hui Liu Yun-fa Lin yong-guang Cheng Song Xue Mao-jia Tang Jian Zhang Jia-yi Fan State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Dongfang Electric Machinery Co. Ltd.Deyang618000China

The load rejection transient process of bulb turbine units is critical to safety of hydropower stations,and determining appropriate closing laws of guide vanes(GVs)and runner blades(RBs)for this process is of *** this study,we proposed a procedure to optimize the co-closing law of GVs and RBs by using computational fluid dynamics(CFD),combined with the design of experiment(DOE)method,approximation model,and genetic optimization *** sensitivity of closing law parameters on the histories of head,speed,and thrust was analyzed,and a two-stage GVs’closing law associating with a linear RBs’closing law was *** results show that GVs dominate the transient characteristics by controlling the change of *** GVs’first-stage closing speed while shortening first-stage closing time can not only significantly reduce the maximum rotational speed but also suppress the water hammer pressure;slowing GVs’second-stage closing speed is conducive to controlling the maximum reverse axial *** directly affect the runner *** RBs’closing speed can further reduce the rotational speed and the maximum reverse axial *** safety margin of each control parameter,flow patterns,and pressure pulsations of a practical hydropower station were all improved after optimization,demonstrating the effectiveness of this method.

关键词： Bulb turbine load rejection transient process double regulation closing law optimization computational fluid dynamics(CFD)

Simultaneous removal of Congo red and cadmium(Ⅱ) from aqueous solutions using graphene oxide–silica composite as a multifunctional adsorbent

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Journal of Environmental Sciences 2020年第12期32卷 151-160页

作者： Ebrahim Mahmoudi Sepehr Azizkhani Abdul Wahab Mohammad law yong ng Abdelbaki Benamor Wei Lun Ang Muneer Ba-Abbad Department of Chemical and Process Engineering Faculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia43600 BangiSelangor Darul EhsanMalaysia Department of Chemical and Environmental Engineering Faculty of EngineeringUniversiti Putra Malaysia43400 SerdangSelangorMalaysia Department of Chemical Engineering Lee Kong Chian Faculty of Engineering and ScienceUniversiti Tunku Abdul RahmanJalan Sungai LongBandar Sungai LongCheras43000 KajangSelangorMalaysia Centre for Sustainable Process Technology(CESPRO) Faculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia43600 BangiSelangor Darul EhsanMalaysia Gas Processing Centre Qatar UniversityP.O.Box 2713DohaQatar

Graphene oxide is a very high capacity adsorbent due to its functional groups and π-π interactions with other compounds. Adsorption capacity of graphene oxide, however, can be further enhanced by having synergistic effects through the use of mixed-matrix composite. In this study, silica-decorated graphene oxide(SGO) was used as a high-efficiency adsorbent to remove Congo red(CR) and Cadmium(Ⅱ) from aqueous solutions. The effects of solution initial concentration(20 to 120 mg/l), solution pH(pH 2 to 7), adsorption duration(0 to 140 min) and temperature(298 to 323 K) were measured in order to optimize the adsorption conditions using the SGO adsorbent. Morphological analysis indicated that the silica nanoparticles could be dispersed uniformly on the graphene oxide surfaces. The maximum capacities of adsorbent for effective removal of Cd(Ⅱ) and CR were 43.45 and 333.33 mg/g based on Freundlich and Langmuir isotherms, respectively. Langmuir and Freundlich isotherms displayed the highest values of Q max for CR and Cd(Ⅱ) adsorption in this study, which indicated monolayer adsorption of CR and multilayer adsorption of Cd(II) onto the SGO, respectively. Thermodynamic study showed that the enthalpy( H) and Gibbs free energy( G) values of the adsorption process for both pollutants were negative, suggesting that the process was spontaneous and exothermic in nature. This study showed active sites of SGO( π-π, hydroxyl, carboxyl, ketone, silane-based functional groups) contributed to an enormous enhancement in simultaneous removal of CR and Cd(Ⅱ) from an aqueous solu-tion, Therefore, SGO can be considered as a promising adsorbent for future water pollution control and removal of hazardous materials from aqueous solutions.

关键词： Graphene-oxide Multifunctional adsorbent Competitive removal Heavy metal-dye removal

Effectiveness of mindfulness-based interventions on the well-being of healthcare workers:a systematic review and meta-analysis

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General Psychiatry 2024年第3期37卷 335-344页

作者： Natasha Yixuan Ong Finn Jing Jie Teo Jane Zi Ying Ee Chun En Yau Julian Thumboo Hiang Khoon Tan Qin Xiang ng NUS yong Loo Lin School of Medicine National University of SingaporeSingapore Health Services Research Unit Singapore General HospitalSingapore SingHealth Duke-NUS Medicine Academic Clinical Programme Duke-NUS Medical SchoolSingapore Singhealth Duke-NUS Global Health Institute Singapore Duke Global Health Institute Duke UniversityDurhamNorth CarolinaUSA Division of Surgery and Surgical Oncology Singapore General HospitalSingapore Saw Swee Hock School of Public Health National University of Singapore and National University Health SystemSingapore

Background Growing evidence attests to the efficacy of mindfulness-based interventions(MBIs),but their effectiveness for healthcare workers remains *** To evaluate the evidence for MBIs in improving healthcare workers’psychological *** A systematic literature search was conducted on Medline,Embase,Cumulative Index for Nursing and Allied Health Literature,PsycINFO and Cochrane Central Register of Controlled Trials up to 31 August 2022 using the keywords‘healthcare worker’,‘doctor’,‘nurse’,‘allied health’,‘mindfulness’,‘wellness’,‘workshop’and‘program’.Randomised controlled trials with a defined MBI focusing on healthcare workers and quantitative outcome measures related to subjective or psychological well-being were eligible for inclusion.R V.4.0.3 was used for data analysis,with the standardised mean difference as the primary outcome,employing DerSimonian and Laird’s random effects *** of Recommendations,Assessment,Development and Evaluation framework was used to evaluate the quality of ***’s Risk of Bias 2 tool was used to assess the risk of bias in the included *** A total of 27 studies with 2506 participants were included,mostly from the USA,involving various healthcare *** such as stress reduction programmes,apps,meditation and training showed small to large effects on anxiety,burnout,stress,depression,psychological distress and job strain outcomes of the *** effects were also seen in self-compassion,empathy,mindfulness and ***,long-term outcomes(1 month or longer postintervention)varied,and the effects were not consistently *** MBIs offer short-term benefits in reducing stress-related symptoms in healthcare *** review also highlights limitations such as intervention heterogeneity,reduced power in specific subgroup analyses and variable study quality.

关键词： nurse sustained workers