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Acta Metallurgica Sinica(English Letters) 2020年第10期33卷 1346-1358页

作者： Yong-Han Li Zhong-Hua Jiang Zhen-Dan Yang jue-shun zhu Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China

A modified tempering treatment has been designed in order to avoid the direct transformation of retained austenite(Ar)during tempering of a low-alloy Cr-Mo-V *** of the direct transformation of Ar into ferrite and M23C6 carbides during conventional tempering at 700℃,transformation into aggregate of ferrite and cementite has been forced by a pre-tempering at 455℃ before conventional *** have been performed on specimens quenched with cooling rates 1.5,3 and 12℃/s,providing different types of Ar within the as-quenched *** results show that the tempering modification does not improve the Charpy impact toughness at the highest quenching rate of 12℃/s,where the specimens cannot incur cleavage cracking induced from fine and discontinuous M23C6 carbides along lath *** the lowest quenching rate 1.5℃/s,the Charpy impact toughness can be improved,and the failure is dominated by carbide aggregates,which originate from the decomposed products of blocky *** is because the tempering modification effectively suppresses the formation of coarse M23C6 carbides at interfaces between the carbide aggregate and bainitic matrix,thereby resulting in a relatively homogeneous distribution of M23C6 carbides inside carbide ***,the tempering modification is recommended for large-scale forgings,in which relatively high quenching rates are difficult to achieve.

关键词： Bainite steel Retained austenite Impact toughness

Modification of Maxwell model for conductivity prediction of carbon nanotubes-filled polymer composites with tunneling effect

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 25-36页

作者： jue zhu Longyuan LI Ningtao zhu Zhejiang Provincial Engineering Research Center for the Safety of Pressure Vessel and Pipeline Key Laboratory of Impact and Safety Engineering (Ningbo University) Ministry of Education School of Engineering Computing and Mathematics University of Plymouth Xi'an Zhanshi Testing & Engineering Co.Ltd.

Carbon nanotubes(CNTs) have garnered great attention in recent years due to their outstanding electrical, thermal, and mechanical properties. The incorporation of small amounts of CNTs in polymers can substantially improve the sensitivity of the polymer's electrical conductivity. This paper presents a modified Maxwell model to evaluate the electrical conductivity of CNTs-filled polymer composites by introducing a transition zone to account for the tunneling effect. In this modified Maxwell model, the CNTs-filled polymer composite is modeled as a three-phase composite, consisting of a matrix(polymer), inclusions(CNTs), and a transition zone(tunneling zone). The effective electrical conductivity(EEC) of the composite is calculated based on the volume fractions and electrical conductivities of the matrix, inclusions, and transition zone. The model's validity is confirmed through the use of available test data, which demonstrates its capability to accurately capture the nonlinear conductivity behavior observed in CNTs-polymer composites. This study offers valuable insights into the design of high-performance conductive polymer nanocomposites, and enhances the understanding of electrical conduction mechanisms in CNT-dispersed polymer composites.

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EQUIVALENT MODEL OF EXPANSION OF CEMENT MORTAR UNDER SULPHATE EROSION

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Acta Mechanica Solida Sinica 2008年第4期21卷 327-332页

作者： jue zhu Minqiang Jiang Jiankang Chen Mechanics and Materials Science Research Center Ningbo University Ningbo 315211 China State Key Laboratory of Nonlinear Mechanics （LNM） Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

The expansion property of cement mortar under the attack of sulfate ions is studied by experimental and theoretical methods. First, cement mortars are fabricated with the ratio of water to cement of 0.4, 0.6, and 0.8. Secondly, the expansion of specimen immerged in sulphate solution is measured at different times. Thirdly, a theoretical model of expansion of cement mortar under sulphate erosion is suggested by virtue of represent volume element method. In this model, the damage evolution due to the interaction between delayed ettringite and cement mortar is taken into account. Finally, the numerical calculation is results indicate that the model perfectly describes performed. The numerical and experimental the expansion of the cement mortar.

关键词： size effect microvoids expansion sodium sulfate attack

TRANSVERSAL INERTIAL EFFECT ON RELAXATION/RETARDATION TIME OF CEMENT MORTAR UNDER HARMONIC WAVE

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Acta Mechanica Solida Sinica 2008年第1期21卷 44-50页

作者： jue zhu Yonghui Cao Jiankang Chen Mechanics and Materials Science Research Center Ningbo University Ningbo 315211 China

Under dynamic loading, the constitutive relation of the cement mortar will be significantly affected by the transversal inertial effect of specimens with large diameters. In this paper, one-dimensional theoretical analysis is carried out to determine the transversal inertial effect on the relaxation/retardation time of the cement mortar under the harmonic wave. Relaxation time or retardation time is obtained by means of the wave velocity, attenuation coefficient and the frequency of the harmonic wave. Thus, the transversal inertial effect on the relaxation time from Maxwell model, as well as on retardation time from Voigt model is analyzed. The results show that the transversal inertial effect may lead to the increase of the relaxation time, but induce the decrease of the retardation time. Those should be taken into account when eliminating the transversal inertial effect in applications.

关键词： cement mortar harmonic wave viscoelastic model relaxation/retardation time

Underlying principle of efficient propulsion in flexible plunging foils

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Acta Mechanica Sinica 2014年第6期30卷 839-845页

作者： Xiao-jue zhu Guo-Wei He Xing Zhang LNM Institute of MechanicsChinese Academy of Sciences

Passive flexibility was found to enhance propulsive efficiency in swimming *** this study,we numerically investigate the roles of structural resonance and hydrodynamic wake resonance in optimizing efficiency of a flexible plunging *** results indicates that（1）optimal efficiency is not necessarily achieved when the driving frequency matches the structural eigenfrequency;（2）optimal efficiency always occurs when the driving frequency matches the wake resonant frequency of the time averaged velocity ***,the underlying principle of efficient propulsion in flexible plunging foil is the hydrodynamic wake resonance,rather than the structural *** addition,we also found that whether the efficiency can be optimized at the structural resonant point depends on the strength of the leading edge vortex relative to that of the trailing edge *** result of this work provides new insights into the role of passive flexibility in flapping-based propulsion.

关键词： Flexibility Propulsive efficiency Structural resonance Hydrodynamic wake resonance

Artificial intelligence in computer-aided diagnosis of abdomen diseases

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Science China(Life Sciences) 2019年第10期62卷 1396-1399页

作者： Fei Gao Yi zhu jue Zhang College of Engineering Peking UniversityBeijing 100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China

The abdomen contains many organs, along with a range of abdominal diseases that require accurate diagnosis. Clinical imaging plays a crucial role in abdominal disease diagnosis, prognosis, and treatment assessment. For decades, physicists have focused on innovation in terms of imaging techniques, assisting radiologists to improve abdominal diseases detection and diagnosis. Consequently, many new imaging methods for abdominal organs have been developed, including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), X-ray, endoscopy, and ultrasound (McAuliffe et al., 2001;Dhawan et al., 2011). Each imaging method has its own unique features. For example, abdominal MRI can achieve the most comprehensive assessment of abdominal lesions, such as the liver, kidney and prostate (Yang et al., 2017;Wang et al., 2018;Gao et al., 2017) mainly due to its diversiform sequences, including structural imaging such as T1 weighted imaging and T2 weighted imaging, as well as diffusion imaging, perfusion imaging, arterial spin labeling and other functional imaging that reflect different functional changes.

关键词： computed tomography magnetic resonance imaging positron emission tomography

Transcriptome research on spermatogenic molecular drive in mammals

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Asian Journal of Andrology 2015年第6期17卷 961-971,I0009页

作者： Zi-jue zhu Shi Yang Zheng Li Department of Urology Ren Ji Hospital School of Medicine Shanghai Jiao Tong University Shanghai 200127 China Department of Andrology Urologic Medical CenterShanghai General Hospital Shanghai Jiao Tong University Shanghai 200080 China Shanghai Key Laboratory of Reproductive Medicine Shanghai 200025 China.

It is known that spermatogenic disorders are associated with genetic deficiency, although the primary mechanism is still unclear. It is difficult to demonstrate the molecular events occurring in testis, which contains germ cells at different developmental stages. However, transcriptomic methods can help us reveal the molecular drive of male gamete generation. Many transcriptomic studies have been performed on rodents by utilizing the timing of the first wave of spermatogenesis, which is not a suitable strategy for research in fertile men. With the development of separation methods for male germ cells, transcriptome research on the molecular drive of spermatogenesis in fertile men has seen great progress, and the results could be ultimately applied to improve the diagnosis and treatment for male infertility.

关键词： GeneChip germ cell RNA-Seq sorting spermatogenesis transcriptome

what drives progressive motor deficits in patients with acute pontine infarction?

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Neural Regeneration Research 2015年第3期10卷 501-504页

作者： jue-bao Li Rui-dong Cheng Liang Zhou Wan-shun Wen Gen-ying zhu Liang Tian Xiang-ming Ye Department of Rehabilitation Medicine Zhejiang Provincial People’s Hospital

Progressive motor deficits are relatively common in acute pontine infarction and frequently associated with increased functional disability. However, the factors that affect the progression of clinical motor weakness are largely unknown. Previous studies have suggested that pontine infarctions are caused mainly by basilar artery stenosis and penetrating artery disease. Recently, lower pons lesions in patients with acute pontine infarctions have been reported to be related to progressive motor deficits, and ensuing that damage to the corticospinal tracts may be respon- sible for the worsening of neurological symptoms. Here, we review studies on motor weakness progression in pontine infarction and discuss the mechanisms that may underlie the neurologic worsening.

关键词： nerve regeneration pontine infarction progressive motor deficits basilar artery pene-trating artery corticospinal tract Wallerian degeneration review neural regeneration

EXPERIMENTAL EVALUATION ON MODULUS OF EQUIVALENT HOMOGENEOUS ETTRINGITE

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Acta Mechanica Solida Sinica 2009年第4期22卷 320-327页

作者： Minghua Zhang Jiankang Chen jue zhu Jiangying Chen Department of Mechanics and Engineering Science Ningbo University Ningbo 315211 China

In the present study, the average modulus of delayed ettringite is evaluated by an experimental method combined with theoretical analysis. Firstly, the delayed ettringite crystal is synthesized by chemical reaction of Aluminum sulfate and calcium hydroxide. Secondly, specimens are obtained by compressing the delayed ettringite crystal under different pre-loads. Thirdly, the variation of the modulus of the specimen with different pre-loads is tested using Instron material test machine and the SHPB technique, respectively. It is found that the experimental data may be suitably fitted by Boltzmann Function. Finally, the porosity of the specimen is detected using the saturation method, and the effect of the porosity on the modulus is analyzed by the Eshelby＇s equivalent inclusion method and the Mori-Tanaka＇s scheme. The static and dynamic modulli of the equivalent homogeneous ettringite obtained in present study are approximately 10.64 GPa and 24.61 GPa, respectively.

关键词： ettringite equivalent homogeneous materials Boltzmann Function modulus

Yrast Bands Calculation for Odd-Odd Nuclei ^(160)Ho, ^(162)Tm and ^(164)Tm

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Chinese Physics Letters 1996年第7期13卷 504-507页

作者： zhu shun-quan ZHENG Ren-rong Department of Physics Southwest Normal UniversityChongqing 630715

In this paper,the axial symmetry rotor plus quasiparticle model is generalized from odd nuclei to odd-odd *** spectra of yrast bands for nuclei ^(160)Ho,^(162)Tm and ^(164)Tm are calculated by using the *** inversions in these three nuclei are reproduced,and one possible signature inversion mechanism connected with the calculation is also discussed.

关键词： method symmetry