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Biomedical and Environmental Sciences 2022年第3期35卷 276-281页

作者： XU Qi zhang Bo LI Xu YE Jia Ming HUO Chuan Yi YIN jian Li zhang Ru Xuan ZHAO wei Sen QI Wen YE Lin Department of Occupational and Environmental Health School of Public HealthJilin UniversityChangchun 130000JilinChina Department of Pediatric Neurology the First Hospital of Jilin UniversityChangchun 130000JilinChina

Neuroblastoma(NB)is the most common extracranial solid tumor of *** accounts for 8%–10%of all malignant tumors in children^([1])and results in a heavy burden to the life and health of *** is a complex disease,and its... 详细信息

关键词： SHSY5Y Transition malignant

Shear behavior of ultrafine magnetite tailings subjected to freeze-thaw cycles

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International Journal of Mining Science and Technology 2019年第4期29卷 609-616页

作者： Chong wei Derek B.Apel Yunhai zhang School of Mining and Petroleum Engineering University of AlbertaEdmontonAlberta T6G 2R3Canada School of Resources and Safety Engineering Central South UniversityChangsha 410083China

To study the shear behavior of the ultrafine magnetite tailings subjected to freeze-thaw cycles,unconsolidated-undrained shear tests were conducted on ultrafine-grained tailings that were subjected to 1-11 cycles of freeze-thaw and defined as a type of clayey silt under confining pressures of 100,200,and 300 *** the number of freeze-thaw cycles,cooling temperature,initial dry density,and moisture content as the four main influencing factors of shear behavior of the tailings samples,the shear stress-strain curve,compression modulus,failure strength,cohesion,and internal friction angle were *** results show that the freeze-thaw cycle has an obvious weakening effect on the shear behavior of the tailings material,and the shear mechanical parameters are affected by a combination of confining pressure,freeze-thaw cycle condition,and initial physical-mechanical properties of the tailings *** the microstructural analysis of the tailings samples subjected to freeze-thaw cycles,it shows that the freeze-thaw cycle mainly affects the porosity,bound water,and arrangement of the tailings ***,the macroscopic changes in shear strength indexes emerge,and then the stability of the tailings dam will decrease.

关键词： Ultrafine magnetite tailings(UMT) Freeze-thaw cycle Shear behavior Triaxial shear test

Mechanical analysis of effective pressure relief protection range of upper protective seam mining

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International Journal of Mining Science and Technology 2017年第3期27卷 537-543页

作者： Yin wei Miao Xiexing zhang Jixiong Zhong Sijian School of Mines Key Laboratory of Deep Coal Resource Ministry of Education China University of Mining & Technology Xuzhou 221116 China State Key Laboratory for Geomechanics & Deep Underground Engineering China University of Mining & Technology Xuzhou 221116 China

This paper analyzes the control mechanism of coal and gas outbursts and proposes the concept of an effective pressure relief protection range, based on the stress relief of the underlying coal-rock mass and the development of a plastic zone. Also this study developed a stress change and fracture development model of the underlying coal-rock mass. In addition, the stress and depth of fracture of any point in the floor were deduced with the application of Maple Calculation Software. The specific engineering parameters of the Pingdingshan No. 12 colliery were applied to determine the relationship between the depth of fracture in the floor and the mining height. The pressure-relief principle of the underlying coal-rock mass was analyzed while varying the mining height of the upper protective seam. The findings indicate that as the depth of fracture in the floor increases, the underlying coal-rock mass experiences a limited amount of pressure relief, and the pressure relief protection range becomes ***, the stress distribution evolves from a ‘‘U" shape into a ‘‘V" shape. A 2.0 m mining height of protective seam situates the outburst-prone seam, Ji_(15), within the effective pressure relief protection range. The fracture development and stress-relief ratio rises to 88%, ensuring the pressure-relief effect as well as economic benefits. The measurement data show that: after mining the upper protective seam, the gas pressure of Ji_(15) dropped from 1.78 to 0.35 MPa, demonstrating agreement between the engineering application and the theoretical calculation.

关键词： Upper protective seam Principle of pressure relief Effective protection range Gas pressure

Acoustic Nanowave Absorption through Clustered Carbon Nanotubes Conveying Fluid

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Acta Mechanica Solida Sinica 2016年第3期29卷 257-270页

作者： Zijun zhang Yongshou Liu Hailong Zhao wei Liu Department of Engineering Mechanics Northwestern Polytechnical University

Absorption of acoustic nanowave in specific frequency region is important for the design of acoustic filter. This paper puts forward a meta material model made up of fluid-conveying carbon nanotubes （CNT）, which can absorb acoustic nanowave in a given frequency range by adjusting the lengths and fluid velocities of themselves. Absorption coefficients are calculated out through the combination of the finite element method with the theoretical model, which are 0.4-0.55 relating to different fluid velocities for the crossing-distributed model. Comparisons are made between the crossed model and the aligned one, which prove that the CNT forest with crossed distribution is more effective in acoustic wave absorption.

关键词： acoustic nanowave absorption meta-material clustered carbon nanotubes

Recent Advances and Progress for the Fabrication and Surface Modification of AIE-active Organic-inorganic Luminescent Composites

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Chinese Journal of Polymer Science 2019年第4期37卷 340-351,I0005页

作者： Liu-Cheng Mao Xiao-Yong zhang Yen wei Department of Chemistry Nanchang University Department of Chemistry and the Tsinghua Center for Frontier Polymer Research Tsinghua University Department of Chemistry and Center for Nanotechnology and Institute of Biomedical Technology Chung-Yuan Christian University

Organic dyes based hybrid organic-inorganic luminescent nanomaterials with high quantum efficiency, good physical or chemical stability, and favorable biocompatibility, have attracted growing attention recently because of their important applications in the areas of biomedical imaging, chemical sensors, and light-emitting diodes(LEDs). Nevertheless, conventional fluorescence molecules suffer from aggregation-caused quenching(ACQ) when they are doped into inorganic nanomaterials. Aggregation-induced emission(AIE) is an abnormal and intriguing fluorescent phenomenon that has aroused increasing interest for various applications especially in biomedical fields. Compared with conventional organic dyes, the AIE-active molecules will emit more intense fluorescence in their aggregates or solid states. It provides an elegant route to overcome the drawbacks of conventional organic molecules. Over the past few decades, the fabrication and surface modification of various organic-inorganic luminescent composites doped with AIE-active molecules have been reported. Therefore, it is highly desirable to summarize these advances. In this review, recent advances and progress in constructing various AIEgens-doped organic-inorganic hybrid nanocomposites and their subsequent surface modification were summarized. We hope this review could further promote the research of AIE-active functional materials.

关键词： Aggregation-induced emission Organic-inorganic luminescent composites Surface modification Biomedical applications

Frequency and Offset Online Estimation of Sinusoidal Signals Based on High-Order Nonlinear Continuous Differentiator

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Chinese Journal of Electronics 2017年第3期26卷 579-584页

作者： WANG Hongwei zhang wei ZUO Junyi WANG Heping School of Aeronautics Northwestern Polytechnical University

Real-time parameter identification of sinusoidal signals is an essential research topic due to its broad utilization in both theoretical studies and engineering practice.A tracking differentiator based online estimation framework has been proposed to simultaneously identify frequencies and offset of given multi-sinusoidal *** differentiator is exploited in presented framework to track the time derivatives of measurements which are then utilized to estimate the frequencies and *** introduce a tracking differentiator called high-order nonlinear continuous differentiator into the framework,giving birth to a new estimation *** experiments on both single and two sinusoidal signal are simulated,indicating the superiority of proposed method on both convergent speed and estimation accuracy.

关键词： Frequency estimation Offset estimation High-order nonlinear continuous differentiator Sinusoidal signal Multi-sinusoidal signal

Adsorption behaviors of strontium using macroporous silica based hexagonal tungsten oxide

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Science China Chemistry 2016年第5期59卷 601-608页

作者： Xiaoxia zhang Yan Wu Hao Wu Yuezhou wei School of Nuclear Science and Engineering Shanghai Jiao Tong University

A novel macroporous silica-based hexagonal tungsten oxide （h-WO3/SiO2） with exchangeable sodium cations located in hex- agonal tunnel structure was synthesized by a facile hydrothermal treatment of sodium tungstate dihydrate with 1 mol/L HCl solution. Utilization of the h-WO3/SiO2 adsorbent to remove aqueous strontium was investigated under the condition of various pH values, contact time, the initial concentration of metal ions, salt ion concentration, and coexisting ions. According to the experimental data, Sr2＋ adsorption equilibrium was achieved within 15 min in acidic solution, and the maximum removal ca- pacity of Sr2＋ occurred at pH 4. The kinetic adsorption of Sr2＋ on h-WO3/SiO2 was controlled by pseudo second-order model, and the saturated adsorption of Sr2＋ on h-WO3/SiO2 was better described by Langmuir and Redlich-Peterson isotherm models compared with the Freundlich isotherm model. The distribution coefficient of St2＋ was more than 2000 cm3/g in the presence of Ca2＋, Mg2＋, La3＋, and Eu3＋, indicating that the h-WO3/SiO2 showed excellent selectivity towards Sr2＋ in pH 4.

关键词： strontium hexagonal tungsten oxide macroporous silica-based support adsorption equilibrium kinetics

Parameters optimum matching of pure electric vehicle dual-mode coupling drive system

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Science China(Technological Sciences) 2014年第11期57卷 2265-2277页

作者： zhang LiPeng LI Liang QI BingNan WANG Chong zhang YaHui SONG jian State Key Laboratory of Automotive Safety and Energy Tsinghua University School of Mechanical and Automotive Engineering Liaocheng University

As an important development direction of pure electric vehicle drive system,the distributed drive system has the advantages of compact structure,high transmission efficiency,and flexible control,but there are some serious problems such as high performance requirements to the drive motors,complex control strategies,and poor *** solve these problems,a two motors dual-mode coupling drive system has been developed at first,which not only has the capacity of two-speed gear shifting,but also can automatically switch between the distributed drive and the centralized drive by means of modes change ***,the performance requirements to the drive motors can be reduced,the problem of abnormal running caused by the fault of unilateral distributed drive systems also can be resolved by replacing the drive mode with centralized ***,the system parameters primary and the optimum matching under the principle of efficiency optimization have been carried out,which makes the drive system achieve predetermined functions and meet the actual demands of different operating *** last,the economic comparison of a pure electric vehicle installation with a dual-mode coupling drive sytem,a single-motor centralized drive system or a dual-motor distributed drive system in the simulation conditions has been *** with other systems,the driving range of the electric vehicle driven by the designed system is significantly increased,which proves the better efficiency and application value of the system.

关键词： pure electric vehicle dual-mode coupling drive system parameter optimum matching genetic algorithm

Comparative study between crack closure model and Willenborg model for fatigue prediction under overload effects

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Chinese Journal of Aeronautics 2016年第6期29卷 1618-1625页

作者： jiang Shan zhang wei He Jingjing Wang Zili Science and Technology on Reliability and Environmental Engineering Laboratory School of Reliability and Systems Engineering Beihang University

A comparative study is performed between a crack closure model and the Willenborg model, which can calculate the fatigue crack growth rate under the overload effects. The modified virtual crack annealing(VCA) model is briefly reviewed, which is based on the equivalent plastic zone concept. In this method, the retardation phenomenon is explained by the crack closure level variation, which is derived from the interactions between forward and reverse plastic zones ahead of the crack tip. As a comparison, the Forman equation in conjunction with the Willenborg model is also reviewed. The retardation phenomenon is described by directly modifying the stress intensity factor. It is known that the large plastic zone created by the overload can decelerate the fatigue crack growth rate until the crack grows beyond this region. A relationship between the plastic zone and the modified stress intensity factor is developed, which is a mathematical fitting equation instead of physical-based formulation. The experimental data in aluminum alloys are used to validate these two models. Overall, good agreement is observed between the model predictions and the testing data. It is noted that the approach based on modified VCA model can give more accurate prediction curves than the Willenborg model.

关键词： Crack closure Fatigue crack growth Interaction effects Overloads Plastic zone

Characteristics and geological significance of the stress state of the lithosphere in the Qinghai-Tibetan Plateau and its neighboring areas

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Science China Earth Sciences 2024年第6期67卷 1836-1855页

作者： Qianwen zhang Ya XU wei CHU Shupeng LU Key Lab of Petroleum Resource Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The present-day lithospheric stress state of the Qinghai-Tibetan Plateau and neighboring areas is controlled by both the lithosphere itself and the underlying *** other words,the stress is affected by the gravitational potential energy(GPE)difference caused by the change in the density distribution within the lithosphere and the drag force on the base of the lithosphere caused by mantle *** study of the lithospheric stress state plays an important role in further understanding the dynamic background and mechanism for the evolution of the Qinghai-Tibetan *** this study,the Crust1.0 crustal density model combined with the S40RTS mantle shear wave velocity variation model was used to calculate the *** EGM2008gravity field model was used to calculate the drag force from mantle convection at the base of the *** lithospheric and joint stress fields of the two sources were obtained by solving the force balance under the thin sheet *** way,we could comprehensively analyze the characteristics of the stress state within the *** regions were classified according to the GPE stress field,mantle drag force stress field,the relative magnitude of the two stress fields,and correlation between the two stress fields and surface *** lithospheric stress fields of the Tarim Basin and other stable blocks are mainly controlled by the GPE *** lithospheric stress field in the collision zone between the Indian Plate and the QinghaiTibetan Plateau is predominantly controlled by the deep mantle drag *** lithospheric stress field in the interior of the Plateau is controlled by both GPE and mantle *** correlation between the lithospheric stress field and surface deformation at the southeast margin of the Qinghai-Tibetan Plateau is *** is hypothesized that the presence of lower crustal flow with lower effective viscosity leads to crust-mantle decoupling,and the mantle drag force has a weaker influe

关键词： Qinghai-Tibetan Plateau Gravitational potential energy Mantle convection Lithospheric deviatoric stress field GPS strain rate field