In this study,3,4-Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate(ECC)and refined Camellia oleifera seed oil(RCOSO)obtained from saponification and acidified hydrolysis has been used as raw materials to perform ...In this study,3,4-Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate(ECC)and refined Camellia oleifera seed oil(RCOSO)obtained from saponification and acidified hydrolysis has been used as raw materials to perform ring-opening reactions for the preparation of cyclohexyl acrylate derivative(CAR).The structure of the synthesized product was characterized using infrared spectroscopy,Raman spectroscopy,and nuclear magnetic resonance spectroscopy.CAR was employed as a plasticizer to produce modified polyvinyl chloride(PVC)films,dioctyl phthalate plasticizer(DOP)used in reference samples to investigate the influence of different plasticizer molecular structures on the properties of PVC films.Observation suggested that(1)CAR plasticizer was successfully synthesized;(2)CAR can interact with PVC,exhibiting good compatibility;(3)PVC films contain CAR showed improved thermal stability,hydrophilicity,and tensile strength.Therefore,CAR has the potential to replace DOP as a plasticizer for PVC.展开更多
为准确表征扣件弹性垫板的非线性动力学性能,将超弹性本构和线性黏弹性本构相结合,同时考虑垫板塑性,建立扣件弹性垫板非线性黏弹性-塑性本构模型;以中国高速铁路WJ-8B型扣件弹性垫板为研究对象,根据垫板的材料特性,结合各种本构模型的...为准确表征扣件弹性垫板的非线性动力学性能,将超弹性本构和线性黏弹性本构相结合,同时考虑垫板塑性,建立扣件弹性垫板非线性黏弹性-塑性本构模型;以中国高速铁路WJ-8B型扣件弹性垫板为研究对象,根据垫板的材料特性,结合各种本构模型的优缺点,分别采用Yeoh模型、Berg摩擦模型和高阶分数阶导数模型(Fraction Voigt and Maxwell model in Parallel,FVMP)对垫板的超弹性、黏弹性和塑性特性进行表征;利用配有高低温试验箱的MFT-250加载系统分别对垫板进行变温静载试验、低频大振幅试验和定频变温试验,求取各本构模型中的参数;通过前述3种试验探究温度对垫板超弹性、黏弹性和塑性的影响。结果表明:当温度高于-40℃时,垫板非线性性质较显著,且垫板所受荷载越大,位移非线性增大趋势越明显;各温度下垫板动态塑性力-位移滞回曲线主刚度与静态力学试验结果变化趋势一致;垫板储能刚度随温度降低逐渐增大,而耗能刚度则随温度降低先增后减,峰值处温度为-46℃;损耗因子在-42℃时达到峰值,约为玻璃化转变温度;非线性黏弹性-塑性模型相较于线性黏弹性-塑性模型拟合效果更好,能全面反映垫板非线性动力学特性;该组合模型可进一步嵌入车辆-轨道耦合动力学仿真平台,为车辆-轨道系统动力学性能优化、减振降噪技术研发提供模型支撑。展开更多
人工耳蜗植入(cochlear implant,CI)是目前治疗双侧重度到极重度感音神经性耳聋最有效的手段。随着手术适应证不断放宽和对双耳听觉的重视,单侧聋患者的双耳听觉重建成为国内外研究热点。单侧聋指听力较差耳平均听阈≥70 dB HL、较好耳...人工耳蜗植入(cochlear implant,CI)是目前治疗双侧重度到极重度感音神经性耳聋最有效的手段。随着手术适应证不断放宽和对双耳听觉的重视,单侧聋患者的双耳听觉重建成为国内外研究热点。单侧聋指听力较差耳平均听阈≥70 dB HL、较好耳平均听阈完全正常的感音神经性耳聋患者;若较好耳平均听阈在30~55 dB HL之间,可称为非对称性感音神经性聋(asymmetrical hearing loss,AHL)[1-2],单侧聋可认为属于AHL的极端情况。单侧聋和AHL患者的聆听困难主要表现在复杂环境中的言语识别、声源定位、耳鸣的困扰以及社交回避等方面。展开更多
基金support from the Scarce and Quality Economic Forest Engineering Technology Research Center(2022GCZX002)the Key Lab.of Biomass Energy and Material,Jiangsu Province(Grant No.JSBEM-S-202305)the Forestry Scientific Research Monitoring Project of Guangdong Province(2025KJXM01).
文摘In this study,3,4-Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate(ECC)and refined Camellia oleifera seed oil(RCOSO)obtained from saponification and acidified hydrolysis has been used as raw materials to perform ring-opening reactions for the preparation of cyclohexyl acrylate derivative(CAR).The structure of the synthesized product was characterized using infrared spectroscopy,Raman spectroscopy,and nuclear magnetic resonance spectroscopy.CAR was employed as a plasticizer to produce modified polyvinyl chloride(PVC)films,dioctyl phthalate plasticizer(DOP)used in reference samples to investigate the influence of different plasticizer molecular structures on the properties of PVC films.Observation suggested that(1)CAR plasticizer was successfully synthesized;(2)CAR can interact with PVC,exhibiting good compatibility;(3)PVC films contain CAR showed improved thermal stability,hydrophilicity,and tensile strength.Therefore,CAR has the potential to replace DOP as a plasticizer for PVC.
文摘为准确表征扣件弹性垫板的非线性动力学性能,将超弹性本构和线性黏弹性本构相结合,同时考虑垫板塑性,建立扣件弹性垫板非线性黏弹性-塑性本构模型;以中国高速铁路WJ-8B型扣件弹性垫板为研究对象,根据垫板的材料特性,结合各种本构模型的优缺点,分别采用Yeoh模型、Berg摩擦模型和高阶分数阶导数模型(Fraction Voigt and Maxwell model in Parallel,FVMP)对垫板的超弹性、黏弹性和塑性特性进行表征;利用配有高低温试验箱的MFT-250加载系统分别对垫板进行变温静载试验、低频大振幅试验和定频变温试验,求取各本构模型中的参数;通过前述3种试验探究温度对垫板超弹性、黏弹性和塑性的影响。结果表明:当温度高于-40℃时,垫板非线性性质较显著,且垫板所受荷载越大,位移非线性增大趋势越明显;各温度下垫板动态塑性力-位移滞回曲线主刚度与静态力学试验结果变化趋势一致;垫板储能刚度随温度降低逐渐增大,而耗能刚度则随温度降低先增后减,峰值处温度为-46℃;损耗因子在-42℃时达到峰值,约为玻璃化转变温度;非线性黏弹性-塑性模型相较于线性黏弹性-塑性模型拟合效果更好,能全面反映垫板非线性动力学特性;该组合模型可进一步嵌入车辆-轨道耦合动力学仿真平台,为车辆-轨道系统动力学性能优化、减振降噪技术研发提供模型支撑。
文摘人工耳蜗植入(cochlear implant,CI)是目前治疗双侧重度到极重度感音神经性耳聋最有效的手段。随着手术适应证不断放宽和对双耳听觉的重视,单侧聋患者的双耳听觉重建成为国内外研究热点。单侧聋指听力较差耳平均听阈≥70 dB HL、较好耳平均听阈完全正常的感音神经性耳聋患者;若较好耳平均听阈在30~55 dB HL之间,可称为非对称性感音神经性聋(asymmetrical hearing loss,AHL)[1-2],单侧聋可认为属于AHL的极端情况。单侧聋和AHL患者的聆听困难主要表现在复杂环境中的言语识别、声源定位、耳鸣的困扰以及社交回避等方面。
