检索结果-南通市图书馆

Science China(Physics,Mechanics & Astronomy) 2016年第3期59卷 89-95页

作者： hua yang Zheng Dao Wang Ya Fang Guo Xing hua Shi Institute of Engineering Mechanics Beijing Jiaotong University State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences

Following deformation, thermally induced shape memory polymers(SMPs) have the ability to recover their original shape with a change in temperature. In this work, the thermomechanical properties and shape memory behaviors of three types of epoxy SMPs with varying curing agent contents were investigated using a molecular dynamics(MD) method. The mechanical properties under uniaxial tension at different temperatures were obtained, and the simulation results compared reasonably with experimental data. In addition, in a thermomechanical cycle, ideal shape memory effects for the three types of SMPs were revealed through the shape frozen and shape recovery responses at low and high temperatures, respectively, indicating that the recovery time is strongly influenced by the ratio of E-51 to 4,4'-Methylenedianiline.

关键词： shape memory polymer molecular dynamics simulation thermomechanics

On Dynamics of Infinitely Generated Contractive Mapping Systems on pZ_p

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2020年第6期36卷 651-662页

作者： Jing hua yang Yun Peng XIAO Department of Mathematics College of SciencesShanghai UniversityShanghai 200444P.R.China

Let p≥2 be a prime number and Zp be the ring of p-adic *** G be a semigroup generated by infinitely many contractive maps on p *** is shown that if G satisfies the open tiling conditions,then there exists a shift transformation on the limit set of G and the shift transformation is ergodic with respect to the Haar measure on p *** an application,we can generalize p-adic Khinchin’s Theorem and p-adic Lochs’Theorem to any infinitely generated semigroup by use of the ergodicity of the shift transformation.

关键词： Contractive maps ergodic limit sets p-adic continued fractions

A Weighted Trudinger–Moser Inequality on R^N and Its Application to Grushin Operator

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2020年第4期36卷 363-378页

作者： Jia Jun WANG Qiao hua yang School of Mathematics and Statistics Wuhan UniversityWuhan 430072P.R.China

Let x=(x',x'')with x'∈Rk and x''∈R^N-k andΩbe a x'-symmetric and bounded domain in R^N(N≥2).We show that if 0≤a≤k-2,then there exists a positive constant C>0 such that for all x'-symmetric function u∈C0^∞(Ω)with∫Ω|■u(x)|^N-a|x'|^-adx≤1,the following uniform inequality holds1/∫Ω|x|^-adx∫Ωe^βa|u|N-a/N-a-1|x'|^-adx≤C,whereβa=(N-a)(2πN/2Γ(k-a/2)Γ(k/2)/Γ(k/2)r(N-a/2))1/***,βa can not be replaced by any greater *** the application,we obtain some weighted Trudinger–Moser inequalities for x-symmetric function on Grushin space.

关键词： Trudinger–Moser inequality Grushin operator sharp constant H-type group

Dihedral influence on lateral–directional dynamic stability on large aspect ratio tailless flying wing aircraft

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2014年第5期27卷 1149-1155页

作者： Song Lei yang hua Zhang yang Zhang Haoyu huang Jun School of Aeronautic Science and Engineering Beihang University AVIC The First Aircraft Institute

The influence of dihedral layout on lateral–directional dynamic stability of the tailless flying wing aircraft is discussed in this paper. A tailless flying wing aircraft with a large aspect ratio is selected as the object of study, and the dihedral angle along the spanwise sections is divided into three segments. The influence of dihedral layouts is studied. Based on the stability derivatives calculated by the vortex lattice method code, the linearized small-disturbance equations of the lateral modes are used to determine the mode dynamic characteristics. By comparing 7056 configurations with different dihedral angle layouts, two groups of stability optimized dihedral layout concepts are created. Flight quality close to Level 2 requirements is achieved in these optimized concepts without any electric stability augmentation system.

关键词： Dihedral angle Flying wing Optimization Stability Tailless

Active disturbance rejection control for hydraulic width control system for rough mill

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) 2007年第9期8卷 1429-1434页

作者： ZOU Jun FU Xin yang hua-yong Institute State Key Laboratoty of Fhtid Power Transmission and Control. Zhejiang University Hangzhou 310027 China

The highly nonlinear behavior of the system limits the performance of classical linear proportional and integral （PI） controllers used for hot rolling. An active disturbance rejection controller is proposed in this paper to deal with the nonlinear problem of hydraulic servo system in order to preserve last response and small overshoot of control system. The active disturbance rejection （ADR） controller is composed of nonlinear tracking differentiator （TD）, extended state observer （ESO） and nonlinear feedback （NF） law. An example of the hydraulic edger system case study is investigated to show the effectiveness and robustness of the proposed nonlinear controller, especially, in the circumstance of foreign disturbance and working condition variation, compared with classic PI controller.

关键词： Active disturbance rejection (ADR) Hydraulic servo system Width control Rough mill

A Normal Criterion Concerning Omitted Holomorphic Function

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2019年第12期35卷 1972-1978页

作者： Jin hua yang Qi yang Xue Cheng PANG School of Mathematical Sciences Xinjiang Normal UniversityUrumqi 830054P.R.China Department of Mathematics East China Normal UniversityShanghai 200062P.R.China

In this paper,we continue to discuss the normality concerning omitted holomorphic function and get the following *** F be a family of meromorphic functions on a domain D,k≥4 be a positive integer,and let a(z)and b(z)be two holomorphic functions on D,where a(z)■0 and f(z)≠∞ whenever a(z)=*** for any f∈F,f'(z)?a(z)f^k(z)≠b(z),then F is normal on D.

关键词： Normal family holomorphic functions omitted functions

Longitudinal dispersive coefficient in channels with aquatic vegetation:A review

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2023年第3期35卷 379-395页

作者： Liu yang Hao-ze Fang Zhong-hua yang Wen-xin huai State Key Laboratory of Water Resources Engineering and Management Wuhan University Wuhan China

The determination of longitudinal dispersion coefficient in rivers is necessary for pollution control,environmental risk assessment,and *** rivers with aquatic vegetation,the flow field is remarkably modified by canopies,which affects velocity profiles and dispersion characteristics dominated by the heterogeneity of the velocity *** dispersion is deduced from lateral and vertical longitudinal velocity gradients for compound channels with vegetated floodplains and rectangular channels with river-wide vegetation,*** many efforts have been exerted to clarify the dispersion process in different conditions and predict the diffusion of contaminants in vegetated rivers,no studies have introduced it *** study reviews the dispersion coefficient characteristics,including magnitude,main impacted factors,and relationships with flow and vegetation features,in channels with aquatic canopies considering the variation of impact factors changing with the different vegetation and river morphology *** typical methodologies for determining longitudinal dispersion coefficients are also summarized to understand the dispersion processes and *** from the pioneer outcomes of previous studies,the review also emphasizes the deficiency of existing studies and suggests possible future directions for improving the theory of dispersion in vegetated channels.

关键词： Vegetated flows longitudinal dispersion coefficient spatial heterogeneity

Young children with multidrug-resistant epilepsy and vagus nerve stimulation responding to perampanel: A case report

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第11期10卷 3511-3517页

作者： hua yang Dan Yu Department of Pediatrics West China Second University HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina

BACKGROUND Perampanel(PER),a third-generation antiepileptic drug,is a selective and noncompetitiveα-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist,and has been approved for the treatment of adults and adolescents with focal ***,there are only a few studies about the efficacy and tolerability of PER in young children with multidrug-resistant *** this case,we aimed to share our clinical experience in this *** SUMMARY A 4-year-old boy without perinatal asphyxia and familial history of epilepsy began to have ictal seizures from age 14 mo,with jerky movement of four limbs and head *** multifocal discharge and background activity were recorded through electroencephalography,and no pathogenic mutation was found in the whole exome sequencing for the patient and his *** had received valproate,levetiracetam,topiramate,oxcarbazepine,clonazepam and lacosamide sequentially at different times,but he still had frequent seizures even after vagus nerve stimulation(VNS)*** was diagnosed with idiopathic multidrug-resistant ***,his seizure frequency was significantly reduced after PER administration in a dose-dependent manner,and better cognitive behavior was *** addition,the adverse reactions of anger and aggression also *** PER is effective as add-on therapy for young children with multidrug-resistant epilepsy who have previously undergone VNS implantation.

关键词： Perampanel Young children Drug-resistant epilepsy Vagus nerve stimulation Case report

Experimental Study on a New Dual-Layer Granular Bed Filter for Removing Particulates

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of China University of Mining and Technology 2007年第2期17卷 201-204页

作者： yang Guo-hua ZHOU Jiang-hua Maritime College Ningbo University Ningbo Zhejiang 315211 China

A new dual-layer granular bed filter for hot gas cleanup was invented and studied experimentally. Fine sand,0.5-1 mm grain size and about 1350 kg/m3 bulk density,was used as the lower layer of the filter. Expanded perlite par-ticles,2-5 mm grain size and about 70 kg/m3 bulk density,was used for the upper layer of the filter in this study. It was confirmed that the sizes and densities of these two media matched well; the binary media remained in complete segre-gation during regeneration by fluidization. Test results show that the filtration of the expanded perlite particle layer was characterized as "deep bed filtration." Filtration of the fine sand layer was "surface cake filtration." The expanded per-lite particle layer contributed about 90% to the bed dust capacity,but only about 20% to the total bed pressure drop,which increased the bed dust capacity ten fold compared to a single-layer bed of the same sand and the same total bed pressure drop. The dust cake on the surface of the fine sand layer raised the collection efficiencies to over 99.99%.

关键词： filtration granular bed filter particulate

New Proposals for Application of Terahertz Imaging Technique in Chinese Medicine

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2022年第4期28卷 366-373页

作者： BAI Shan-shan yang hua-yuan School of Acupuncture Moxibustion and Tuina Shanghai University of Traditional Chinese MedicineShanghai201203China

The rapid development of terahertz technology promotes the realization of various terahertz imaging *** technology features terahertz waves as good non-invasive illumination sources due to their high spectral resolution,penetration and *** terahertz imaging technique(TIT)has gradually been extended from the biomedical field to the field of Chinese medicine(CM),and it has become a powerful tool for seeking scientific evidence for CM theories with the use of modern science and *** paper reviews the current application of TITs in the field of CM research,and most importantly offers novel proposals for the application of TITs in CM research from the perspective of CM syndrome objectification and acupuncture research and cites existing reports as reference to the feasibility of these new proposals.

关键词： terahertz Chinese medicine syndrome objectification meridians acupuncture moxibustion new proposals