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Calculation of the Physical and Microdosimetric Parameters of Electron and Alpha-Particle Radiation Using Monte Carlo Simulations

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Chinese Physics Letters 2014年第3期31卷 181-183页

作者： GENG Jin-Peng CAO tian-guang LI Duo-Fang AN Hai-Long HAN Ying-Rong LI Jin HU Jin-Shan LI Nan-Nan zhan Yong Institute of Biophysics School of Sciences Hebei University of Technology Tianjin 300401

Various ionizing radiations, such as electrons and alpha particles, transfer their energy to media by produced secondary electrons and induce double- or single-strand break of DNA, which result in variable effects. To understand how the ionizing radiations interact with DNA and break it, several models have been developed, most of them consider the water as a vapor state. Actually, the ionizing particles interact with DNA which is solved in liquid water. To compare the difference of vapor and liquid water models, we calculate the stopping power, continuous slowing down approximation （CSDA） range and S value of electrons and alpha particles at cellular scale in liquid and vapor by Monte Carlo simulations, respectively. Our data show that the stopping power and CSDA range are different in liquid and vapor water in a special energy range. For many S values, the liquid model is better than the vapor model when the energy of the electrons is higher than 100 keV and the vapor model is higher than the liquid model for the 1 MeV alpha particles.

关键词： DNA

Effects of acupuncture on hypothalamic–pituitary–adrenal axis:Current status and future perspectives

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Journal of Integrative Medicine 2024年第4期22卷 445-458页

作者： Jia-yuan Zheng Jing Zhu Yu Wang zhan-zhuang tian Department of Integrative Medicine and Neurobiology School of Basic Medical SciencesState Key Laboratory of Medical Neurobiology and Ministry of Education Frontiers Center for Brain ScienceInstitutes of Brain ScienceInstitute of Acupuncture ResearchAcademy of Integrative MedicineShanghai Key Laboratory for Acupuncture Mechanism and Acupoint FunctionShanghai Medical CollegeFudan UniversityShanghai 200032China Department of Human Anatomy School of Integrative MedicineShanghai University of Traditional Chinese MedicineShanghai 201203China

The hypothalamic–pituitary–adrenal(HPA) axis is a critical component of the neuroendocrine system,playing a central role in regulating the body's stress response and modulating various physiological processes. Dysregulation of HPA axis function disrupts the neuroendocrine equilibrium, resulting in impaired physiological functions. Acupuncture is recognized as a non-pharmacological type of therapy which has been confirmed to play an important role in modulating the HPA axis and thus favorably targets diseases with abnormal activation of the HPA axis. With numerous studies reporting the promising efficacy of acupuncture for neuroendocrine disorders, a comprehensive review in terms of the underlying molecular mechanism for acupuncture, especially in regulating the HPA axis, is currently in need. This review fills the need and summarizes recent breakthroughs, from the basic principles and the pathological changes of HPA axis dysfunction, to the molecular mechanisms by which acupuncture regulates the HPA axis. These mechanisms include the modulation of multiple neurotransmitters and their receptors, neuropeptides and their receptors, and microRNAs in the paraventricular nucleus,hippocampus, amygdala and pituitary gland, which alleviate the hyperfunctioning of the HPA *** review comprehensively summarizes the mechanism of acupuncture in regulating HPA axis dysfunction for the first time, providing new targets and prospects for further exploration of acupuncture.

关键词： Acupuncture Electroacupuncture Hypothalamic-pituitary-adrenal axis Mechanism Neurotransmitter microRNA

Characterization of the key aroma compounds in four varieties of pomegranate juice by gas chromatography-mass spectrometry(GC-MS),gas chromatography-olfactometry(GC-O),odor activity value(OAV),aroma recombination,and omission tests

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Food Science and Human Wellness 2023年第1期12卷 151-160页

作者： Cong Lu Yuyu zhang Ping zhan Peng Wang Honglei tian College of Food Engineering and Nutritional Science Shaanxi Normal UniversityXi’an 710119China Beijing Key Laboratory of Flavor Chemistry Beijing Technology and Business UniversityBeijing 100048China

P omegranate(Punica granatum L.)has attracted considerable attention in world markets due to its valuable nutrients and highly appreciated sensory *** aroma profiles of 4 varieties of pomegranate juice,including Dahongtian(DP),Jingpitian(JP),Luyudan(LP),and tianhonngdan(TP),were investigated via gas chromatography-mass spectrometry(GC-MS)and gas chromatography-olfactometry(GC-O)analyses.A total of 43 volatile compounds were identified by using *** these compounds,16 were considered as potential aroma-active compounds as detected by *** compounds belonged to the classes of terpinenes,alcohols,and *** volatile compounds were defined as the main contributors to the overall aroma of pomegranate juice due to their high odor activity values(OAVs≥1).Aroma recombination and omission tests confirmed thatβ-myrcene,1-hexanol,and(Z)-3-hexen-1-ol were the key aroma compounds,and limonene,1-octen-3-ol,linalool,and hexanal were important aroma-active compounds in DP samples.

关键词： Pomegranate juice Aroma-active compounds GC-MS GC-O Odor active value(OAV) Omission tests

A study of the effect of local scour on the flow field near the spur dike

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Theoretical & Applied Mechanics Letters 2024年第2期14卷 98-105页

作者： Yu-tian Li Jie-Min zhan Wing-Hong Onyx Wai Department of Industrial Design School of Industrial Design and Ceramic ArtFoshan UniversityFoshan 528000China Department of Applied Mechanics and Engineering Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China

The flow field near a spur dike such as down flow and horseshoe vortex system(HVS)are susceptible to the topographic changes in the local scouring process,resulting in variation of the sediment transport with *** this study,large eddy simulations with fixed-bed at different scouring stages were conducted to investigate the changes in flow *** results imply that the bed deformation leads to an increase in flow rate per unit area,which represent the capability of sediment transportation by water,in the scour ***,the intensity of turbulent kinetic energy and bimodal motion near the sand bed induced by the HVS were also ***,the peak moments between the two sediment transport mechanisms were ***,understanding the complex feedback mechanism between topography and flow field is essential for the local scour problem.

关键词： Spur dike Local scour Large eddy simulation Down flow Horseshoe vortex system

Spatially-separated and photo-enhanced semiconductor corrosion processes for high-efficient and contamination-free electrochemical nanoimprint lithography

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Science China Chemistry 2022年第4期65卷 810-820页

作者： Hantao Xu Lianhuan Han Jian-Jia Su Zhong-Qun tian Dongping zhan Key Laboratory of Physical Chemistry of Solid Surfaces(PCOSS) Engineering Research Center of Electrochemical Technologies of Ministry of EducationDepartment of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Department of Mechanical and Electrical Engineering School of Aerospace EngineeringXiamen UniversityXiamen 361005China

Free of any thermoplastic or photocuring resists, electrochemical nanoimprint lithography(ECNL) has emerged as an alternative nanoimprint way to fabricate three-dimensional micro/nano-structures(3D-MNSs) directly on a semiconductor wafer by a spatially-confined corrosion reaction induced by the metal/semiconductor contact potential. However, the consumption of electron acceptors in the ultrathin electrolyte between imprint mold and semiconductor wafer will slow down or even cease the corrosion rate. To solve this problem, we change the short-circuited corrosion cell into a spatially-separated primary cell: the imprint mold compacted gallium arsenide(GaAs) wafer in the anodic chamber while the platinum(Pt) plate connected to the imprint mold in the cathodic chamber. Thus, the GaAs corrosion rate will be stabilized in its limiting steady-state current density because of the abundant source of electron acceptors in the catholic chamber. The corrosion processes can be photo-enhanced by white-light illumination. Consequently, both the accuracy and the efficiency are promoted dramatically, which are demonstrated by the excellent performance of the fabricated binary optical elements. Moreover, the contamination problem caused by the electron acceptors is totally avoided. All the results prove that this novel ECNL mode is competitive and prospective in imprinting 3D-MNSs directly on semiconductor wafer.

关键词： nanoimprint lithography electrochemical microfabrication semiconductor corrosion semiconductor microdevices 3D functional micro/nano-structures

Upper Bound Solution of the Resisting Moment Bearing Capacity of A Composite Bucket Shallow Foundation of An Offshore Wind Turbine in Sand

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China Ocean Engineering 2022年第6期36卷 859-870页

作者： LIU Run LI tian-liang CHEN guang-si LIAN Ji-jian State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China

Bearing the large moment that is generated by the wind load that acts on the upper structure of offshore wind turbines is an important feature of their foundations that is different from other offshore structures.A composite bucket shallow foundation(CBSF)has been proposed by tianjin University to address the soft geological conditions in the offshore regions of China for wind *** CBSF is a new type of foundation and is effective against large *** soil deformation test of a CBSF and the numerical simulation study under the same working conditions are carried out to determine the failure mechanism of a CBSF under moment *** resisting soil compression rateηm is defined as a new empirical parameter that indicates the ability of the soil inside the bucket to resist moment *** upper limit of the resisting moment bearing capacity of the bucket foundation is derived through the upper bound theorem of classical plasticity theory based on the failure *** calculation method is validated by tests of bucket models with different height-diameter ratios in sand under moment loading.

关键词： bucket foundation failure mechanism resisting moment bearing capacity upper bound theorem resisting soil compression rate

Effect of austempering time on microstructure and properties of a low-carbon bainite steel

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International Journal of Minerals,Metallurgy and Materials 2020年第3期27卷 340-346页

作者： Man Liu guang Xu Jun-yu tian Qing Yuan Xin Chen The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology

The effect of austempering time after the bainitic transformation on the microstructure and property in a low-carbon bainite steel was investigated by metallography and dilatometry. The results showed that by prolonging the austempering time after the bainite transformation, the amount of large-size martensite/austenite islands decreased, but no significant change of the amount and morphology of bainite were observed. In addition, more austenite with a high carbon content was retained by prolonging the holding time at the bainite transformation ***, with a longer holding time, the elongation was improved at the expense of a small decrease in tensile strength. Finally, the Avrami equation B(RF) = 1-exp(-0.0499 × t^0.7616) for bainite reaction at 350℃ was obtained for the tested steel. The work provided a reference for tailoring the properties of low-carbon steels.

关键词： austempering time retained austenite martensite/austenite island low-carbon bainite transformation kinetics

Tunable perpendicular anisotropic magnetoresistance in CoO/Co/Pt heterostructures

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Rare Metals 2023年第2期42卷 579-584页

作者： Qian-Qian Liu guang Yang Jing-Yan zhang Guo-Nan Feng Chun Feng Qian zhan Ming-Hua Li guang-Hua Yu Department of Materials Physics and Chemistry University of Science and Technology BeijingBeijing100083China

Transport properties of magnetron-sputtered CoO/Co/Pt heterostructures were investigated by physical property measurement *** types of magnetoresistance are observed in the heterostructures,including isotropic anisotropic magnetoresistance(AMR),AMR with geometric size effect,and interfacial effect.A reversal in sign of perpendicular AMR is found in the film CoO(3 nm)/Co(3 nm)/Pt(3 nm)compared to the film CoO(3 nm)/Co(3 nm)/CoO(3 nm),which is associated with ***,perpendicular AMR is tunable in the films CoO(3 nm)/Co(3 nm)/CoO(t)/Pt(3 nm)and CoO(3 nm)/Co(3 nm)/Pt(t)/CoO(3 nm)at will,with either positive or negative value,by varying the inserting layer *** electronic structure information of the samples was measured by X-ray photoelectron spectroscopy(XPS).The spin-related transport and XPS results manifest that magnetic proximity effect,surface scattering,together with oxygen migration contribute to the tunable function of Pt.

关键词： Perpendicular anisotropic magnetoresistance Magnetic proximity effect Surface scattering X-ray photoelectron spectroscopy

Synergistic Cu single-atoms and clusters on tubular carbon nitride for efficient photocatalytic performances

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Rare Metals 2024年第11期43卷 5891-5904页

作者： Yu-Xiao Feng Hui-Jun Yu tian-guang Lu Zi-Ye Zheng Shuang tian Li Xiang Shan Zhao Shu-guang Wang Zuo-Li He Shandong Key Laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and EngineeringShandong UniversityQingdao 266237China Weihai Research Institute of Industrial Technology of Shandong University Shandong UniversityWeihai 264209China School of Electrical Engineering Shandong UniversityJinan 250061China CEDAR Knight Cancer InstituteSchool of MedicineOregon Health and Science UniversityPortland 97201USA

Metal clusters or even single-atoms dispersed and anchored on the photocatalysts'surface can enhance photocatalytic performances on organic pollutant ***,a simple photoreduction method was used to create atomically dispersed metal single-atoms/clusters(MSCs,M=Cu,Pd,Au and Ag)on P-modulated tubular carbon nitride(TCN).The obtained MSCs@TCN demonstrated excellent photocatalytic performances for the degradation of sulfamethazine(SMZ).In particular,the photocatalyst with 2 wt%Cu loading showed ultrahigh SMZ oxidation efficiency(k=0.06110 min^(-1)),almost three times that of TCN(k=0.02066 min^(-1)).It also shows excellent stability in the 5th-cycle *** improved photocatalytic activity of the CuSCs@TCN is ascribed to the synergistic promotion of photogenerated charge separation by Cu single-atoms/clusters as active sites,accelerated charge transfer from bulk TCN to Cu sites through Cu-N_(x)***,the active sites of Cu single-atoms/clusters could promote the production of·O_(2)^(-),which participates in organic oxidation with strong oxidizing holes(h^(+)).This strategy paves a new avenue for designing high-performance photocatalysts decorated with metal single-atoms and clusters.

关键词： Carbon nitride Photocatalysis Cu single-atom Sulfamethazine Degradation