检索结果-南通市图书馆

science china(Technological sciences) 2009年第3期52卷 584-589页

作者： xu yepeng1 & zhou ding2.1 school of science, nanjing {2. of science and Technology, nanjing 2.0094, china 2.College of Civil Engineering, nanjing {2. of Technology, nanjing 2.0009, china school of science Nanjing University of Science and Technology Nanjing China College of Civil Engineering Nanjing University of Technology Nanjing China

This paper studies the bending of simple-supported rectangular plate on point supports, line supports and elastic foundation. On the basis of three-dimensional elasticity theory, the exact expressions of the displacement functions, which satisfy the governing differential equations and the simply supported boundary conditions at four edges of the plate, are analytically derived. The reaction forces of the in- termediate supports are regarded as the unknown external forces acting on the lower surface of the plate. The unknown coefficients are then determined by the boundary conditions on the upper and lower surfaces of the plate. Comparing the numerical results obtained from the proposed method to those obtained from Kirchhoff plate theory, Mindlin plate theory and those obtained from the commer- cial finite element software ANSYS, the high accuracy of the present method has been demonstrated.

关键词： rectangular plate point support line support elastic foundation displacement stress three-dimensional elasticity solution

Influence of the penetration of adjacent X-section cast-in-place concrete(XCC)pile on the existing XCC pile in sand

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang university-science A(Applied Physics & Engineering) 2024年第7期25卷 557-572页

作者： Peng zhou Jianhui xu Changjie xu Guangwei CAO Jie CUP xuanming ding school of Civil Engineering and Architecture State Key Laboratory of Performance Monitoring and Protecting of Rail Transit InfrastructureEast China Jiaotong UniversityNanchang330013China Guangdong Key Laboratory of Earthquake Engineering and Application Technology Earthquake Engineering Research&Test CenterGuangzhou UniversityGuangzhou510006China Key Laboratory of New Technology for the Construction of Cities in Mountain Areas College of Civil EngineeringChongqing UniversityChongqing400045China Zijin school of Geology and Mining Fuzhou UniversityFuzhou350116China

A series of small-scale 1g X-section cast-in-place concrete(XCC)pile-penetration model tests were conducted to study the effects of soil density and pile geometry on the lateral responses of an existing pile and the variations in surrounding soil *** results showed that the bending patterns of existing XCC piles varied with penetration *** lateral response of the existing pile was sensitive to the change in relative density and pile *** example,the bending moment of the existing pile increased along with these *** development of the radial stressσ′r/σ′v0 of the soil around an existing pile showed different trends at various depths during the penetration of the adjacent ***,the change in radial stress during the penetration of the XCC pile did not exhibit the“h/R effect”that was observed in the free-field soil,due to the shielding effect of the existing *** peak value of radial stressσ′r_max/σ′v0 decreased exponentially as the radial distance r/R *** attenuation ofσ′r_max/σ′v0 with r/R in the loose sand was faster than in the medium-dense or dense ***σ′r_max/σ′v0 at the same soil location increased with the cross-section geometry parameter.

关键词： X-section cast-in-place concrete(XCC)pile Test Penetration Sand Lateral response Radial stress

Enhancing cellular behavior in repaired tissue via silk fibroin-integrated triboelectric nanogenerators

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第3期10卷 137-147页

作者： Zhelin Li Shuxing xu Zijie xu Sheng Shu Guanlin Liu Jianda {2. ding Lin Wei Tang Changsha Aier Eye Hospital Aier School of OphthalmologyCentral South UniversityChangshaHunanChina The Xiangya Hospital Central South UniversityChangshaHunanChina Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China Center on Nanoenergy Research School of Physical Science&TechnologyGuangxi UniversityNanning 530004China school of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049China Department of Plastic Surgery the Third Xiangya HospitalChangshaHunanChina

Triboelectric nanogenerators(TENGs)have emerged as a promising approach for generating electricity and providing electrical stimuli in medical electronic *** their potential benefits,the clinical implementation of TENGs faces challenges such as skin compliance and a lack of comprehensive assessment regarding their biosafety and ***,further research is imperative to overcome these limitations and unlock the full potential of TENGs in various biomedical *** this study,we present a flexible silk fibroin-based triboelectric nanogenerator(SFB-TENG)that features an on-skin substrate and is characterized by excellent skin compliance and air/water *** range of electrical output generated by the SFB-TENG was shown to facilitate the migration and proliferation of Hy92.,NIH-3T3 and RSC96 ***,apoptosis of fibroblast NIH-3T3 cells was observed when the output voltage increased to more than 2. V at a frequency of 2.*** addition,the moderate electrical stimulation provided by the SFB-TENG promoted the cell proliferation cycle in Hy92. *** research highlights the efficacy of a TENG system featuring a flexible and skin-friendly design,as well as its safe operating conditions for use in biomedical *** findings position TENGs as highly promising candidates for practical applications in the field of tissue regeneration.

关键词： overcome spite generating

A novel stiffness optimization model of space telescopic boom based on locking mechanism

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2024年第3期19卷 41-59页

作者： Kun xu Xinghan ZHUANG zhou SU Qiuhong LIN Shouzhi REN Hang XIAO Xilun {2. school of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Beijing Institute of Spacecraft System Engineering Beijing 100094China

The deployable telescopic boom,whose mass and stiffness play crucial roles,is extensively used in the design of space-deployable ***,the most existing optimal design that neglects the influence of the locking mechanisms in boom joints cannot raise the whole stiffness while reducing the boom *** tackle this challenge,a novel optimization model,which utilizes the arrangement of the locking mechanisms to achieve synchronous improvement of the stiffness and mass,is *** proposed optimization model incorporates a novel joint stiffness model developed based on an equivalent parallel mechanism that enables the consideration of multiple internal stiffness factors of the locking mechanisms and tubes,resulting in more accurate representations of the joint stiffness *** analysis shows that the proposed stiffness model achieves more than at least 11% improved accuracy compared with existing ***,case verification shows that the proposed optimization model can improve stiffness while effectively reducing mass,and it is applied in boom optimization design.

关键词： deployable telescopic boom locking mechanism stiffness model clearance error optimization model

Oxidative cyclization of allyl compounds and isocyanide: A facile entry to polysubstituted 2.cyanopyrroles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第4期35卷 330-335页

作者： Yaping Zhang Wei zhou Mingchun Gao Tianqi Liu Bingxin Liu Chang-Hua ding Bin {2. Department of Chemistry Affiliated Nantong Hospital of Shanghai University(The Sixth People's Hospital of Nantong)Shanghai Engineering Research Center of Organ RepairInnovative Drug Research CenterSchool of MedicineShanghai UniversityShanghai 200444China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

A facile Tf OH-catalyzed oxidative cyclization of allyl compounds and isocyanide has been developed with the assistance of DDQ, where isocyanide is used as the crucial "N" and "CN" sources. Highly functionalized 2.cyanopyrroles are constructed efficiently through a new formal [3 + 2. mode, demonstrating diverse reactivity and synthetic utility in organic chemistry. 2.Cyanopyrrole is converted into a nucleobase analogue of Remdesivir and 5H-pyrrolo[2.1-a]isoindole through a three-step or a two-step sequence, respectively. This protocol features broad substrate scope, operational simplicity and good functional group tolerance.

关键词： Isocyanide Cyanopyrrole Insertion Allyl compound Bronsted acid catalysis

Growth,optical dispersion and magnetic behavior of Dy^(3+) doped yttrium iron garnet crystals

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第6期42卷 1110-1117,I0004页

作者： Yating Fang Hui Shen Yudie Ma Shijie Liao Shuang Xia Tian Tian ding zhou Yunfeng Ma Jiayue {2. Institute of Crystal Growth School of Materials Science and EngineeringShanghai Institute of Technology National Engineering Center of Electromagnetic Radiation Control Materials School of Electronic Science and EngineeringUniversity of Electronic Science and Technology of China

Y_(3)Fe_(5)O_(12.(YIG)crystals are highly desirable for the fabrication of mid-infrared isolators with the rapid growth of optical communications,although it is rather challenging to grow large size and high-quality single ***^(3+)doping is expected to improve the optical and magneto-optical prope ***,high quality Dy:YIG crystals and the adjustment of Dy^(3+)on the structure and optical behavior of YIG crystal remain unclear,impeding its practical ***,a series of Y_(3-x)Dy_(x)Fe_(5)O_(12.(x=0,0.5,1.0,1.5,3)solid solution crystals was grown by the flux-Bridgman method and single crystals up to 2. mm were *** the introduction of Dy^(3+),lattice parameters are gradually enlarged from 1.2.79 nm(YIG)to 1.2.2. nm(DyIG).Typical Dy^(3+)absorption peaks are observed around 1070,12.5 and 1670 *** refractive index decreases from 2.37(500 nm)to 2.10(2.00 nm)for YIG crystal,and it reduces from 2.47(500 nm)to 2.16(2.00 nm)for DyIG *** optical bandgaps remain almost unchanged for Dy:YIG *** optical dispersion of the refractive indices was finely fitted by the Wemple and DiDomenico(WDD)and the Sellmeier models,*** the increase of Dy^(3+)content,the saturation magnetization(Ms)decreases significantly from 2..62.emu/g(YIG)to 5.33 emu/g(DyIG).Small coercive field is persisted for this system,endowing small external magnetic *** results provide valuable references for the manipulation of rare earths on the properties of magnetooptical crystals,which is beneficial to the design of high-performance garnet crystals for the application of optical switching and non-reciprocal related devices.

关键词： Magneto-optical crystal Yttrium iron garnet Dy^(3+)doping Crystal growth Optical dispersion Rare earths

Technologies and studies of gas exchange in two-stroke aircraft piston engine:A review

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第1期37卷 24-50页

作者： Yu zhou xueyu LI Shuiting {2. Shuai ZHAO Kun ZHU Longtao SHAO Farong DU Gerui WANG Zheng xu Research Institute of Aero-Engine Beihang UniversityBeijing 100191China Aircraft/Engine Integrated System Safety Beijing Key Laboratory Beijing 100191China school of Transportation science and Engineering Beihang UniversityBeijing 100191China Civil Aviation university of china Tianjin 300300China Aero Engine Academy of china Beijing 101304China school of Energy and Power Engineering Beihang UniversityBeijing 100191China Beihang Hangzhou Innovation Institute Yuhang Hangzhou 310052China

The in-cylinder gas exchange process is crucial to the power performance of two-stroke aircraft piston engines,which is easily influenced by complex factors such as high-altitude performance variation and in-cylinder flow *** paper reviews the development history and characteristics of gas exchange types,as well as the current state of theory and the validation methods of gas exchange technology,while also discusses the trends of cutting-edge technologies in the *** paper provides a theoretical foundation for the optimization and engineering design of gas exchange systems and,more importantly,points out that the innovation of gas exchange types,the modification of theoretical models,and the technology of variable airflow organization are the key future research directions in this field.

关键词： Aircraft piston engine Aircraft power systems Gas exchange High-altitude performance In-cylinder flow Two-stroke Unmanned Aerial Vehicles(UAVs)

Bolstering the Mechanical Robustness of Supramolecular Polymer Network by Mechanical Bond

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer science 2024年第10期42卷 1536-1544,I0012页

作者： Yuan-Hao Wang Jing-Xi Deng Jun Zhao Yi ding Li Yang Zhao-Ming Zhang xu-{2. Yan school of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai200240China Frontiers science Center for Transformative Molecules Shanghai Jiao Tong UniversityShanghai200240China

Supramolecular polymer networks(SPNs)are celebrated for their dynamic nature,yet they often exhibit inadequate mechanical *** far,the quest to bolster the mechanical resilience of SPNs while preserving their dynamic character presents a formidable ***,we introduce[2.rotaxane into SPN to serve as another cross-link,which could effectively enhance the mechanical robustness of the polymer network without losing the dynamic *** with SPN,the dually cross-linked network(DPN)demonstrates superior breaking strength,Young’s modulus,puncture force and toughness,underscoring its superior ***,the cyclic tensile tests reveal that the energy dissipation capacity of DPN rivals,and in some cases surpasses,that of SPN,owing to the efficient energy dissipation pathway facilitated by[2.*** addition,benefiting from stable topological structure of[2.rotaxane,DPN exhibits accelerated recovery from deformation,indicating superior elasticity compared to *** strategy elevates the performance of SPNs across multiple metrics,presenting a promising avenue for the development of high-performance dynamic materials.

关键词： Rotaxane cross-links Dually cross-linked network Supramolecular polymer network Host-guest recognition Dynamic materials

Optoelectronic tuning of plasmon resonances via optically modulated hot electrons

在线全文

学校读者我要写书评

暂无评论

National science Review 2024年第5期11卷 134-141页

作者： Jiacheng Yao Cheng Wang Chi Zhang Song Ma Li zhou Ti Wang Ququan Wang Hongxing xu Tao {2. Key Laboratory of Artificial Micro Nano Structure of Ministry of Education School of Physics and Technology Wuhan University Department of Physics Southern University of Science and Technology

Fast optical modulation of nanoplasmonics is fundamental for on-chip integration of all-optical *** various strategies have been proposed for dynamic modulation of surface plasmons, critical issues of device compatibility and extremely low efficiency in the visible spectrum hamper the application of optoplasmonic nanochips. Here we establish an optoplasmonic system based on Au@Cu2.xS hybrid core–shell nanoparticles. The optical excitation of hot electrons and their charge transfer to the semiconductor coating(Cu2.xS) lead to lowered electron density of Au, which results in the red shift of the localized surface plasmon resonance. The hot electrons can also transport through the Cu2.xS layer to the metal substrate, which increases the conductance of the nanogap. As such, the coupled gap plasmon blue-shifts with a magnitude of up to ～15 nm, depending on the excitation power and the thickness of the coatings, which agrees with numerical simulations. All of this optoelectronic tuning process is highly reversible, controllable and fast with a modulated laser beam, which is highly compatible and sufficiently useful for on-chip integration of nanophotonic devices.

关键词： hot carriers plasmon switching optoplasmonics circuit modelNPoM

A comprehensive aerodynamic-thermalmechanical design method for fast response turbocharger applied in aviation piston engines

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Propulsion and Power Research 2024年第2期13卷 145-165页

作者： Yu zhou Yue Song Shuai Zhao xueyu Li Longtao Shao Huansong Yan Zheng xu Shuiting ding Research Institute of Aero-Engine Beihang UniversityBeijing 100083China Aircraft/Engine Integrated System Safety Beijing Key Laboratory Beijing 100083China school of Energy and Power Engineering Beihang UniversityBeijing 100083China school of Transportation science and Engineering Beihang UniversityBeijing 100083China AVIC nanjing Engineering Institute of Aircraft Systems Nanjing 210000China Hangzhou International Innovation Institute Beihang UniversityHangzhou 311115China Civil Aviation university of china Tianjin 300300China

Limited by the poor transient response performance of turbochargers,the dynamic performance of aviation piston engines tends to *** a bid to enhance the turbocharger’s acceleration capabilities,this study scrutinizes various factors impacting its *** on the operational principles and transient response process of the turbocharger,three types of in-ertiadnamely,aerodynamic inertia(ADI),thermal inertia(TI),and mechanical inertia(MI)d are identiﬁed and addressed for *** begin,this paper pioneers the innovative deﬁnition of a method for evaluating the transient response performance of the *** method incor-porates the introduction of an ADI parameter,inspired by the deﬁnition of ***,a thin-walled volute design with a low Biot number and a lightweight turbine impeller is introduced to reduce the turbocharger’s TI and *** simulation results of theﬂowﬁeld distribution within the volute and diffuser demonstrate the comprehensive design method’s effectiveness in improving gas pressure and temperature distributions in these ***,the pressure distributionﬂuctuation in the constant moment-of-momentum volute(CMV)is 62.8%lower than that in the constant velocity moment volute(CVMV).The low-TI thin-walled volute not only en-hances the turbocharger’s response speed but also reduces its weight by approximately 40%.The impact of three types of inertia on the engine’s response speed is quantiﬁed as follows:ADI(94%)>MI(5%)>TI(1%).This conclusion has been veriﬁed through test results of both the turbocharger and the *** design method not only signiﬁcantly improves the turbo-charger’s response performance but also offers valuable insights for the optimal design of other blade mechanical systems.

关键词： Turbocharger Fast response design method Aerodynamic inertia Thermal inertia Mechanical inertia