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SYNTHESIS OF AROMATIC DIAMINE-BASED BENZOXAZINES AND EFFECT OF THEIR BACKBONE STRUCTURE ON THERMAL AND FLAMMABILITY PROPERTIES OF POLYMERS

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Chinese Journal of Polymer Science 2013年第10期31卷 1359-1371页

作者： Tao Zhang hong-qiang yan Zheng-ping Fang Mao Peng MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University Department of Packaging Engineering College of Materials and Textiles Zhejiang Sci-tech University Lab of Polymer Materials and Engineering Ningbo Institute of Technology Zhejiang University

Three kinds of novel aromatic diamine-based benzoxazines containing naphthalene, propane-2,2-diyldibenzene and neopentyl groups in the backbone, respectively （designated as BAPNCP, BAPBACP and BAPNPGCP, respectively）, were synthesized and characterized. In addition, the effects of backbone structures on curing behaviors of the monomers and thermal and flammability properties of the resulting polymers were systematically studied. The results indicated that BAPNPGCP displayed the highest enthalpy of the curing reaction associated with the ring-opening of benzoxazine, which was due to the effect of benzoxazine ring content per unit mass. Interestingly, the 5 wt% weight loss temperature and char residue after thermogravimetric test for poly（BAPNPGCP） were 8 ℃ and 7% higher than those of poly（BAPBACP）. Meanwhile, the total heat release of poly（BAPNPGCP） was less than half of that for poly（BAPBACP）, indicating the substantial effect of benzoxazine ring content on flammability and char formation. Furthermore, it was found that poly（BAPNCP） gave the best thermal stability and flame retardancy, which was due to the synergistic effect between naphthalene group and benzoxazine ring content. This study provides new insight into the curing behavior of benzoxazine and further understanding on the high performance of polybenzoxazine.

关键词： Aromatic diamine-based benzoxazine Thermal properties Flammability properties.

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Flame-retardant Coating by Alternate Assembly of Poly(vinylphosphonic acid) and Polyethylenimine for Ramie Fabrics

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Chinese Journal of Polymer Science 2014年第3期32卷 305-314页

作者： Li-li Wang Tao Zhang hong-qiang yan 彭懋 Zheng-ping Fang yan Li Wang Hao MOE Key Laboratory of Macromolecular Synthesis and Functionalization Institute of Polymer CompositesZhejiang University Laboratory of Polymer Materials and Engineering Ningbo Institute of TechnologyZhejiang University School of Aerospace Engineering and Applied Mechanics Tongji University Centre of Excellence in Engineered Fibre Composites University of Southern Queensland

A novel intumescent flame retardant coating, consisting of poly（vinylphosphonic acid）（PVPA） as the acid source and branched polyethylenimine （BPEI） as the blowing agent, was constructed on the surface of ramie fabrics by alternate assembly to remarkably improve the flame retardancy of ramie. The PVPA/BPEI coating on the surface of individual fibers of ramie fabric pyrolyzes to form protective char layer upon heating/burning and improves the flame retardancy of ramie. Thermogravimetric analysis reveals that the PVPA/BPEI-coated ramie fabrics left as much as 25.8 wt% residue at 600 ~C, while the control （uncoated） fabric left less than 1.4 wt% residue. Vertical flame test shows that all PVPA/BPEI-coated fabrics have shorter after-flame time, and the residues well preserved the original weave structure and fiber morphology, whereas, the uncoated fabric left only ashes. Microscale combustion calorimetry shows that the PVPA/BPEI coatings greatly reduce the total heat release by as much as 66% and the heat release capacity by 76%, relative to those of the uncoated fabric.

关键词： Alternative assembly Poly(vinylphosphonic acid) Flame retardant Ramie fabric.

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PEI/PAA/APP三组分膨胀组装涂层阻燃改性苎麻织物

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高分子学报 2017年第6期27卷 982-989页

作者：赵黎闫红强方征平浙江大学宁波理工学院宁波315100 高分子合成与功能构造教育部重点实验室浙江大学高分子科学与工程学系杭州310027

利用聚乙烯亚胺(PEI)的正电荷性及聚磷酸铵(APP)和聚丙烯酸(PAA)的负电荷性,通过层层组装技术在柔顺多孔的苎麻织物表面交替构筑了(PEI/PAA/PEI/APP)n膨胀型阻燃涂层,并对处理前后的苎麻织物的热稳定性和阻燃性等性质进行了表征.热失重... 详细信息

利用聚乙烯亚胺(PEI)的正电荷性及聚磷酸铵(APP)和聚丙烯酸(PAA)的负电荷性,通过层层组装技术在柔顺多孔的苎麻织物表面交替构筑了(PEI/PAA/PEI/APP)n膨胀型阻燃涂层,并对处理前后的苎麻织物的热稳定性和阻燃性等性质进行了表征.热失重分析(TGA)、微型量热仪(MCC)以及垂直燃烧测试(VFT)结果表明,阻燃处理后织物的热稳定性和阻燃性显著提高.同时与(PEI/APP)n试样相比,引入不同浓度的第3组分PAA在组装层数较少时通过增加PEI的电荷密度等作用可有效增加吸附量从而使上述性能有所提高,层数较高时由于APP和PAA的同性电荷紊乱,阻燃性的提升受到限制.

关键词：阻燃性热性能苎麻织物层层组装多组分

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Change of Visual Acuity and Related Factors in Idiopathic Optic Neuritis

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Eye Science 2001年第1期17卷 46-49页

作者： Changxian Yi, Linjie Guo, Jiexiong Ou, hong yan, qiang YuZhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences Guangzhou, 510060, China Zhongshan Ophthalmic Center Sun Yat-sen University of Medical Sciences

Purpose : To study the change of visual acuity and related factors in idiopathic optic neuritis.Methods: Retrospectively studying 136 cases (210 eyes) of idiopathic optic neuritis hospitalized in our department during last 5 years. The data was analyzed with the methods of multivariate stepwise regression analysis by SPSS statistic package.Results: The final visual acuity was very strongly related positively to the initial visual acuity at the time point of starting treatment and negatively to the time span beginning the treatment to the time showing improvement, age of patient and the duration from onset of the disorder to the time point of treatment beginning.Conclusions: Promptly right treatment can significantly change the natural course and the final vision of optic neuritis. Severe visual loss, old age, longer time without right therapy and slow improvement after the treatment may indicate an unfavorable final visual recovery. The different dosages of steroid applied in this study was not significant in view of the final visual acuity. Eye Sience 2001; 17: 46 ～ 49.

关键词：先天性视神经炎视力影响因素诊断药物治疗

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“Zero‑Strain” NiNb_(2)O_(6) Fibers for All‑Climate Lithium Storage

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Nano-Micro Letters 2025年第1期17卷 348-360页

作者： yan Zhao qiang Yuan Liting yang Guisheng Liang Yifeng Cheng Limin Wu Chunfu Lin Renchao Che College of Physics Donghua UniversityShanghai 201620People’s Republic of China School of Materials Science and Engineering Institute of Materials for Energy and EnvironmentQingdao UniversityQingdao 266071People’s Republic of China Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsAcademy for Engineering&TechnologyFudan UniversityShanghai 200438People’s Republic of China Zhejiang Laboratory Hangzhou 311100People’s Republic of China Inner Mongolia University Hohhot 010021People’s Republic of China

Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte ***,their moderate unit-cellvolume expansion(generally 5%–10%)during Li^(+)storage causes unsatisfactory long-term ***,“zero-strain”NiNb_(2)O_(6) fibers are explored as a new anode material with comprehensively good electrochemical *** Li^(+)storage,the expansion of electrochemical inactive NiO_(6) octahedra almost fully offsets the shrinkage of active NbO_(6) octahedra through reversible O *** superior volume-accommodation capability of the NiO_(6) layers guarantees the“zero-strain”behavior of NiNb_(2)O_(6) in a broad temperature range(0.53%//0.51%//0.74%at 25//−10//60℃),leading to the excellent cyclability of the NiNb_(2)O_(6) fibers(92.8%//99.2%//91.1%capacity retention after 1000//2000//1000 cycles at 10C and 25//−10//60℃).This NiNb_(2)O_(6) material further exhibits a large reversible capacity(300//184//318 mAh g−1 at 0.1C and 25//−10//60℃)and outstanding rate performance(10 to 0.5C capacity percentage of 64.3%//50.0%//65.4%at 25//−10//60℃).Therefore,the NiNb_(2)O_(6) fibers are especially suitable for large-capacity,fast-charging,long-life,and all-climate lithium-ion batteries.

关键词： NiNb_(2)O_(6)porous fiber “Zero-strain”mechanism Electrochemical property Harsh-temperature operation Operando characterization

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Human-induced pluripotent stem cell-derived neural stem cell exosomes improve blood-brain barrier function after intracerebral hemorrhage by activating astrocytes via PI3K/AKT/MCP-1 axis

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Neural Regeneration Research 2025年第2期20卷 518-532页

作者： Conglin Wang Fangyuan Cheng Zhaoli Han Bo yan Pan Liao Zhenyu Yin Xintong Ge Dai Li Rongrong Zhong qiang Liu Fanglian Chen Ping Lei Department of Geriatrics Tianjin Medical University General HospitalTianjinChina School of Medicine Nankai UniversityTianjinChina Tianjin Neurological Institute TianjinChina

Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor ***-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)have shown potential for brain injury repair in central nervous system *** this study,we explored the impact of hiPSC-NSC-Exos on blood-brain barrier preservation and the underlying *** results indicated that intranasal delivery of hiPSC-NSC-Exos mitigated neurological deficits,enhanced blood-brain barrier integrity,and reduced leukocyte infiltration in a mouse model of intracerebral ***,hiPSC-NSC-Exos decreased immune cell infiltration,activated astrocytes,and decreased the secretion of inflammatory cytokines like monocyte chemoattractant protein-1,macrophage inflammatory protein-1α,and tumor necrosis factor-αpost-intracerebral hemorrhage,thereby improving the inflammatory *** sequencing indicated that hiPSC-NSC-Exo activated the PI3K/AKT signaling pathway in astrocytes and decreased monocyte chemoattractant protein-1 secretion,thereby improving blood-brain barrier *** with the PI3K/AKT inhibitor LY294002 or the monocyte chemoattractant protein-1 neutralizing agent C1142 abolished these *** summary,our findings suggest that hiPSC-NSC-Exos maintains blood-brain barrier integrity,in part by downregulating monocyte chemoattractant protein-1 secretion through activation of the PI3K/AKT signaling pathway in astrocytes.

关键词： AKT astrocyte blood-brain barrier cerebral edema exosomes human-induced pluripotent stem cells intracerebral hemorrhage neural stem cells neuroinflammation PI3K

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Life-cycle assessment and techno-economic analysis of the production of wood vinegar from Eucommia stem: a case study

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Frontiers of Chemical Science and Engineering 2023年第8期17卷 1109-1121页

作者： Ji-Lu Zheng Ya-hong Zhu yan-yan Dong Ming-qiang Zhu College of Forestry Northwest A&F UniversityYangling 712100China College of Mechanical and Electronic Engineering Northwest A&F UniversityYangling 712100China Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081China

This research undertook a case study of the life-cycle assessment and techno-economic analysis of the slow pyrolysis of Eucommia stem for the production of wood vinegar and activated *** results showed that the production of one ton of wood vinegar via the slow pyrolysis of Eucommia stem show comparatively low global warming potential(2.37×10^(2) kg CO_(2) eq),primary energy demand(3.16×10^(3) MJ),acidification potential(2.19 kg SO2 eq),antimony depletion potential(3.86×10^(–4) kg antimony eq),and ozone depletion potential(7.46×10^(–6) kg CFC-11 eq)and was more environmentally friendly than the production of dilute acetic acid(12 wt%)via petrochemical ***,the total capital investment,total product cost,and cash flowsheet were provided in the techno-economic ***,the net present value,internal rate of return,and dynamic payback period of the production process were *** findings indicated that while this production process is cost-effective,it might not be economically attractive or could generate investment *** increase in the added value of the wood vinegar and the activated carbon could remarkably improve the economic feasibility of this production process.

关键词： life-cycle assessment techno-economic analysis wood vinegar activated carbon Eucommia

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Two-stage reduction for the preparation of ferronickel alloy from nickel laterite ore with low Co and high MgO contents

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International Journal of Minerals,Metallurgy and Materials 2017年第5期24卷 512-522页

作者： Yong-qiang Chen hong-liang Zhao Cheng-yan Wang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Key Lab of Rare & Precious Metals Green Recycling and Extraction

The preparation of ferronickel alloy from the nickel laterite ore with low Co and high MgO contents was studied by using a pre-reduction-smelting method. The effects of reduction time, calcination temperature, quantity of reductant and calcium oxide (CaO), and pellet diameter on the reduction ratio of Fe and on the pellet strength were investigated. The results show that, for a roasting temperature > 800 A degrees C, a roasting time > 30 min, 1.5wt% added anthracite coal, 5wt% added CaO, and a pellet size of similar to 10 mm, the reduction ratio of Fe exceeds 70% and the compressive strength of the pellets exceeds 10 kg per pellet. Reduction smelting experiments were performed by varying the smelting time, temperature, quantity of reductant and CaO, and reduction ratio of Fe in the pellets. Optimal conditions for the reduction smelting process are as follows: smelting time, 30-45 min; smelting temperature, 1550A degrees C; quantity of reductant, 4wt%-5wt%; and quantity of CaO, 5wt%; leading to an Fe reduction ratio of 75% in the pellets. In addition, the mineral composition of the raw ore and that during the reduction process were investigated by process mineralogy.

关键词： pre-reduction smelting ferronickel alloy nickel laterite ore

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A novel high-efficient P/N/Si-containing APP-based flame retardant with a silane coupling agent in its molecular structure for epoxy resin

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Chinese Journal of Chemical Engineering 2023年第3期55卷 137-147页

作者： qiang Sun Jinlei Wang Xue Meng Jie Zhang hong yan College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Interface Science and Engineering in Advanced Materials(Taiyuan University of Technology) Ministry of EducationTaiyuan 030024China

A flame retardant containing multiple antiflaming elements usually exhibits high-efficient flame retardancy. Here, a novel P/N/Si-containing ammonium polyphosphate derivative(APTES-APP) is synthesized from ammonium polyphosphate(APP) and silane coupling agent(3-aminopropyl)triethoxysilane(APTES)via cation exchange, which is quite different in the chemical structure from APTES-modified APP for retaining silicon hydroxyls. APTES-APP is highly efficient for the epoxy resin. 8%(mass) APTES-APP imparts excellent flame retardancy to the epoxy resin, with a V-0 rating at the UL-94 test(1.6 mm)and an LOI value of 26%(vol). The peak heat release rate and total smoke production of the flameretardant epoxy resin are decreased by 68.1% and 31.3%, respectively. The synergy of P/N/Si contributes to the well-expanded char residue with a strong and dense surface layer, which is a very good barrier against heat and mass transfer. Besides, there is no significant deterioration in the mechanical properties of flame-retardant epoxy resin thanks to silicon hydroxyls forming hydrogen bonds with epoxy molecules. Meanwhile, other molecules can be grafted onto APTES-APP via these silicon hydroxyls, if ***, this work has developed a new strategy for amino silane as flame retardants. In conjunction with a low-cost and simple preparation method, APTES-APP has a promising prospect in the high-performance flame-retardant epoxy.

关键词： Ammonium polyphosphate Silane coupling agent All-in-one system Flame retardancy Epoxy resin

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Development of steel dampers for bridges to allow large displacement through a vertical free mechanism

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Earthquake Engineering and Engineering Vibration 2014年第3期13卷 375-388页

作者： Pan Peng yan hong Wang Tao Xu Peizhen Xie qiang Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry Department of Civil Engineering Tsinghua University China Shanghai Architectural Design & Research Institute CO. Ltd. Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering Mechanics China Earthquake Administration School of Civil Engineering Qingdao Technological University Department of Building Engineering Tongji University

Isolation bearings and dampers are often installed between piers and superstructures to reduce the seismic responses of bridges under large earthquakes. This paper presents a novel steel damper for bridges. The damper employs steel plates as energy dissipation components, and adopts a vertical free mechanism to achieve a large deformation capacity. Quasi-static tests using displacement-controlled cyclic loading and numerical analyses using a finite element program called ABAQUS are conducted to investigate the behavior of the damper, and a design methodology is proposed based on the tests and numerical analyses. Major conclusions obtained from this study are as follows：（1） the new dampers have stable hysteresis behavior under large displacements; （2） finite element analyses are able to simulate the behavior of the damper with satisfactory accuracy; and （3） simplified design methodology of the damper is effective.

关键词： steel damper large deformation bridge cyclic loading numerical simulation

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