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Science China Chemistry 2008年第11期51卷 1127-1131页

作者： sun dazhi CHEN Jing Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 102201China

N,N-dimethyl-3-oxa-glutaramic acid was purified and characterized by 1H-NMR, Fourier transform in-frared spectroscopy (FT-IR) and elemental analysis. The thermal decomposition of the title compound was studied by means of thermogravimetry differential thermogravimetry (TG-DTG) and FT-IR. The ki-netic parameters of its second-stage decomposition reaction were calculated and the decomposition mechanism was discussed. The kinetic model function in a differential form, apparent activation energy and pre-exponential constant of the reaction are 3/2 [(1-α) 1/3-1]-1, 203.75 kJ-mol-1 and 1017.95s-1, respec-tively. The values of ΔS≠, ΔH≠ andΔG≠ of the reaction are 94.28 J-mol-1-K-1, 203.75 kJ-mol-1 and 155.75 kJ-mol-1, respectively.

关键词： decomposition N N-dimethyl-3-oxa-glutaramic acid kinetics

Dispersion–tribological property relationship in mineral oils containing 2D layered α-zirconium phosphate nanoplatelets

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Friction 2020年第4期8卷 695-707页

作者： Feng JIANG Haoyang sun Lei CHEN Fan LEI dazhi sun Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China

Inorganic nanomaterials exhibit superior friction-reduction and anti-wear properties in oils. In this study, 2D layered α-zirconium phosphate (α-ZrP) nanosheets intercalated with different amines have been synthesized to study their dispersion stabilities in lubricating oil and tribological applications. The intercalated amines should be sufficiently long and lipophilic to provide stabilization to α-ZrP nanosheets in mineral oil. The results of tribological tests illustrate that with the addition of well-dispersed nanosheets, the coefficient of friction (COF) and pin volume loss reduce by ~47% and 75%, respectively. The excellent dispersion stability enables the nanosheets to flow into the contact area at the beginning, and thereby protect the rubbing surface. A reduction in the van der Waals forces between the adjacent layers induced by the intercalated amines transforms the friction between adjacent layers from pin disk to sliding, leading to a decrease in the COF under hydrodynamic lubrication. The study provides a new method to enhance the tribological properties via tuning the dispersion stabilities of nanomaterials in oils.

关键词： friction-reduction and anti-wear nanoadditive layered nanosheet α-zirconium phosphate(α-ZrP) dispersion tribology

Impacts of cell phone use on driving safety and drivers'perception of risk

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Journal of Modern Transportation 2016年第2期24卷 145-152页

作者： dazhi sun Anxi Jia Texas A&M University-Kingsville KingsvilleTXUSA

In this study, the factors influencing phone-related driving safety and drivers＇ perceptions of cell phone usage were analyzed. A representative sample of more than 500 licensed drivers in Texas who own a cell phone was interviewed based on a well-design questionnaire. Logistic regression model showed that the impact of using cell phone on driving safety varies depending on the characteristics of drivers, such as gender, age, driving experience, and use intensity. Additionally, the results indicated that the strong determinants of phone-related hazard are different from that of phone-related accidents. Regarding the drivers＇ perception of cell phone usage, there are two key findings. First, there is no explicit belief among the drivers about whether cell phone usage impairs driving safety regardless of the drivers＇ age, gender, driving education experience etc. Second, most of drivers have not realized that cell phone use while driving would increase their perception reaction time. Based on the analysis of these results, implications of cell phone use on driving safety along with some safety countermeasures, such as selective bans and non-cell phone zones, are discussed in the paper.

关键词： Cell phone Phone-related hazard Phonerelated accident

Application Value of Multimodal Magnetic Resonance Imaging in the Diagnosis of Atypical Hepatocellular Carcinoma

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Chinese Journal of Biomedical Engineering(English Edition) 2020年第3期29卷 33-39页

作者： Bo Li Naixin Wang dazhi sun Lixin Liu Department of Radiology Tianjin Third Central HospitalTianjin 300170China

Objective This study aims to explore the application value of multimodal magnetic resonance imaging(MRI)in the diagnosis of atypical hepatocellular carcinoma(HCC).Methods 80 patients with atypical HCC who were admitted to our hospital from August 2018 to February 2020 were selected as the research *** patients underwent dynamic computed tomography(CT)enhancement scans,and then multimodal MRI scans,including an MRI plain scan,dynamic contrastenhancement(DCE),and diffusion-weighted imaging(DWI).Then,the image data were *** The diagnostic accuracy of the observation group(95.00%)was significantly higher than that of the control group(75.00%).This difference was statistically significant(χ2=6.128,P<0.05).With the increase of the b value,the apparent diffusion coefficient(ADC)values of the liver tissue and liver cancer tissue gradually *** with normal liver tissue,the ADC value of liver cancer tissue was significantly lower than that of normal liver tissue(P<0.05).A plain MRI scan of 89 lesions,DCE examination of 93 lesions,(1)7 lesions were slow-rising and fast-falling;(2)72 lesions were fast-rising and fast-falling;(3)10 were platform-type lesions;(4)4 lesions had no *** The diagnostic efficiency of a multimodal MRI in the diagnosis of atypical HCC is high,and it has particular clinical application value.

关键词： Multimodal magnetic resonance imaging Hepatocellular carcinoma Atypical manifestations Diffusion-weighted imaging Dynamic contrast-enhanced

In-depth analysis of traffic congestion using computational fluid dynamics (CFD) modeling method

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Journal of Modern Transportation 2011年第1期19卷 58-67页

作者： dazhi sun Jinpeng LV S. Travis WALLER Department of Civil ＆ Architectural Engineering Texas A＆M University-Kingsville Texas 78363 USA Department of Civil Engineering The University of Texas at Austin Austin Texas 78712 USA

This paper introduces computational fluid used in aerospace engineering, to deal with surface physical and mathematical foundations of CFD, this traffic problems such as queue/platoon distribution, dynamics （CFD）, a numerical traffic flow related problems. approach widely and successfully After a brief introduction of the paper develops CFD implementation methodology for modeling shockwave propagation, and prediction of system performance. Some theoretical and practical applications are discussed in this paper to illustrate the implementation methodology. It is found that CFD approach can facilitate a superior insight into the formation and propagation of congestion, thereby supporting more effective methods to alleviate congestion. In addition, CFD approach is found capable of assessing freeway system performance using less ITS detectors, and enhancing the coverage and reliability of a traffic detection system.

关键词： CFD Euler's equation shockwaves queue/platoon system performance monitoring

N,N-二甲基-3-氧杂-戊酰胺酸热分解及非等温动力学

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清华大学学报（自然科学版） 2005年第12期45卷 1650-1653页

作者：孙大陟陈靖清华大学核能及新能源技术研究院北京102201

为提供三烷基氧膦(TRPO)简化流程中N,N-二甲基-3-氧杂-戊酰胺酸(DOGA)反萃液后续处理的依据,纯化并表征了DOGA, 并对其热分解过程及非等温动力学进行了研究.实验采用热重-微分热重为主要手段.研究表明: DOGA中含有一个结晶水;其热分解... 详细信息

为提供三烷基氧膦(TRPO)简化流程中N,N-二甲基-3-氧杂-戊酰胺酸(DOGA)反萃液后续处理的依据,纯化并表征了DOGA, 并对其热分解过程及非等温动力学进行了研究.实验采用热重-微分热重为主要手段.研究表明: DOGA中含有一个结晶水;其热分解分两步进行,在40～90 ℃范围内脱去结晶水,在150～260 ℃范围内完全分解;脱水过程属于三维扩散,机理函数为Zhuralev-Lepelman-Tempelman方程;分解过程属于三维扩散,机理函数为Ginsling-Brownstein方程. 获得了相应的动力学方程.

关键词：非等温动力学 N,N-二甲基-3-氧杂-戊酰胺酸结晶水热分解

Graphene foam/hydrogel scaffolds for regeneration of peripheral nerve using ADSCs in a diabetic mouse model

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Nano Research 2022年第4期15卷 3434-3445页

作者： Qun Huang Yuting Cai Xinrui Yang Weimin Li Hongji Pu Zhenjing Liu Hongwei Liu Mohsen Tamtaji Feng Xu Liyuan Sheng Tae-Hyung Kim Shiqing Zhao dazhi sun Jinbao Qin Zhengtang Luo Xinwu Lu Department of Vascular Surgery Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineShanghai 200011China Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices Department of Materials Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China Vascular Center of Shanghai Jiao Tong University Shanghai 200011China Department of Chemical and Biological Engineering and William Mong Institute of Nano Science and Technologythe Hong Kong University of Science and TechnologyHong Kong 999077China Bioinspired Engineering and Biomechanics Center(BEBC) the Key Laboratory of Biomedical Information Engineering of Ministry of EducationSchool of Life Science and TechnologyXi'an Jiaotong UniversityXi'an 710049China Shenzhen Institute Peking UniversityShenzhen 518057China School of Integrative Engineering Chung-Ang UniversitySeoul 06974Republic of Korea School of Biomedical Engineering Shanghai Jiao Tong UniversityShanghai 200030China

The functional recovery of peripheral nerve injury(PNI)is unsatisfactory,whereas diabetes mellitus(DM)and its related complications further attenuate the restoration of diabetic PNI(DPNI).Adipose-derived stem cells(ADSCs)are promising candidates for treatment of DPNI due to their abundant source,excellent differentiation and paracrine *** results showed that ADSCs remarkably enhanced the proliferation and migration of Schwann cells and endothelial cells,and tube ***,ADSCs could regulate Nrf2/HO-1,NF-κB and PI3K/AKT/mTOR signaling pathways,showing multiple functions in reducing oxidative stress and inflammation,and regulating cell metabolism,growth,survival,proliferation,angiogenesis,differentiation of Schwann cell and myelin *** current study,novel graphene foam(GF)/hydrogel-based scaffold was developed to deliver ADSCs for treatment of ***/hydrogel scaffold exhibited excellent mechanical strength,suitable porous network,superior electrical conductivity,and good *** vitro results revealed that GF/hydrogel scaffold could obviously accelerate proliferation of Schwann ***,in vivo experiments demonstrated that ADSCs-loaded GF/hydrogel scaffold significantly promoted the recovery of DPNI and inhibited the atrophy of targeted muscles,thus providing a novel and attractive therapeutic approach for DPNI patients.

关键词： peripheral nerve injury(PNI) diabetes mellitus(DM) adipose-derived stem cells(ADSCs) graphene hydrogel scaffold

Magnetic and Dielectric Properties of BST/BF Multiferroic Ceramic Materials

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材料科学与工程（中英文A版） 2016年第5期6卷 270-276页

作者： Yabo Zhang Pingstm Qiu Yubai Pan Jinrong Lin Feifei Wang Yanxue Tang Xiyun He dazhi sun Department of Chemistry Shanghai Normal University 100 Guilin Road Shanghai 200234 China Shanghai Institute of Ceramics Chinese Academy of Sciences 1295 DingxiRoad Shanghai 200050 China

Effect of Polyethylene (LDPE) Microplastic on Remediation of Cadmium Contaminated Soil by <i>Solanum nigrum</i>L.

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Journal of Geoscience and Environment Protection 2022年第1期10卷 49-64页

作者： Jiying Zou Chenyu Wang Jianwei Li Jia Wei Ying Liu Liangyu Hu Hui Liu Hongfeng Bian dazhi sun College of Resource and Environmental Engineering Jilin Institute of Chemical Technology Jilin China College of Land Science and Technology China Agricultural University Beijing China School of Environment Northeast Normal University Changchun China Yangtze River Shipping Public Security Bureau Wuhan China

Solanum nigrum L. has a delightful prospect as a hyperaccumulation plant for cadmium pollution remediation, and microplastic is a new type of pollution that has received wide attention. In this study, the effects of polyethylene microplastics (LDPE) (0.135, 0.27, 0.81 and 1.35 mg·kg-1) and cadmium (20 mg·kg-1) on the growth indexes and soil physical and chemical properties of Solanum nigrum L. were investigated in a 17-day microcosm experiment. The results showed that single LDPE contamination showed a trend of low concentration promotion and medium-high concentration inhibited the growth index of Solanum nigrum L. and soil physicochemical index, and single Cd contamination was more stressful to plants than single LDPE contamination, while low concentration of LDPE could reduce the effect of Cd on soil physical and chemical properties and promote plant growth and uptake of soil nutrients. These findings suggest that high concentrations of microplastics can inhibit the growth of Solanum nigrum L. alone or in combination with Cd, rather than reducing the toxicity of Cd.

关键词： Microplastics Heavy Metal Compound Pollution Phytoremediation Solanum nigrum L.

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22MnB5超高强钢热冲压成形工艺及试验

中国机械工程 2017年第12期28卷 1498-1503,1511页

作者：薛克敏孙大智李萍巩子天纵合肥工业大学材料科学与工程学院合肥230009

考虑材料的热物理性能参数、力学性能与温度的关系,利用ABAQUS软件建立了22MnB5超高强钢热冲压过程的热力耦合有限元模型,选用合适的热冲压工艺参数进行数值分析,得到了坯料热冲压成形的应力应变分布,并以板料初始温度为变量,研究不同... 详细信息

考虑材料的热物理性能参数、力学性能与温度的关系,利用ABAQUS软件建立了22MnB5超高强钢热冲压过程的热力耦合有限元模型,选用合适的热冲压工艺参数进行数值分析,得到了坯料热冲压成形的应力应变分布,并以板料初始温度为变量,研究不同初始温度对零件厚度分布、回弹及冷却速率的影响。进行了板料初始温度为900℃的22MnB5超高强钢热冲压试验,零件厚度分布及回弹量与模拟结果基本吻合,各区域淬火组织均为板条状马氏体,由于零件底部的淬火冷却速率较大,马氏体组织更加均匀细小。

关键词： 22MnB5超高强钢数值模拟回弹马氏体转变