以废打印机壳PC/ABS再生粒子(R-PC/ABS)为基体材料,对苯二酚双(二苯基磷酸脂)(HDP)和梯形倍半硅氧烷(TSQ)为阻燃剂,采用熔融共混制备了无卤阻燃PC/ABS,对其阻燃性能、力学性能、尺寸稳定性和负荷热变形温度(HDT)进行分析,结果发现,TSQ...以废打印机壳PC/ABS再生粒子(R-PC/ABS)为基体材料,对苯二酚双(二苯基磷酸脂)(HDP)和梯形倍半硅氧烷(TSQ)为阻燃剂,采用熔融共混制备了无卤阻燃PC/ABS,对其阻燃性能、力学性能、尺寸稳定性和负荷热变形温度(HDT)进行分析,结果发现,TSQ可以阻燃R-PC/ABS,并且,对力学性能、尺寸稳定性和HDT影响较小,R-PC/ABS/0.8TSQ的LOI为29.8%,阻燃达到3.0 mm V-0和2.0 mm V-1级;HDP可以有效地阻燃R-PC/ABS,但是,对力学性能、尺寸稳定性和HDT的负面影响较大,R-PC/ABS/12HDP的LOI为36.1%,阻燃可达到UL 941.0 mm V-0级,与R-PC/ABS相比,HDT、拉伸强度、弯曲强度、弯曲模量和缺口冲击强度分别降低了20.2℃、26.6%、14.5%、16.9%和60.9%;R-PC/ABS/0.8TSQ/6HDP的LOI为35.7%,阻燃级别达到UL 941.0 mm V-0级,与R-PC/ABS/12HDP相比,模后收缩率(PMS)降低了19.7%,HDT、拉伸强度、弯曲强度、弯曲模量和缺口冲击强度分别提高了13℃、21.0%、11.3%、14.3%和85.9%。展开更多
以钛酸四丁酯水解反应原位生成的TiO_(2)包覆微胶囊红磷(microcapsulated red phosphorus,TDP)为主体阻燃剂,开展PC/ABS合金的协效阻燃研究。以PC/ABS阻燃复合材料的LOI值、UL-94等级为主要考察指标,筛选并确定较适宜的TDP基三元协效复...以钛酸四丁酯水解反应原位生成的TiO_(2)包覆微胶囊红磷(microcapsulated red phosphorus,TDP)为主体阻燃剂,开展PC/ABS合金的协效阻燃研究。以PC/ABS阻燃复合材料的LOI值、UL-94等级为主要考察指标,筛选并确定较适宜的TDP基三元协效复合阻燃剂及其质量配比为TDP∶ZnO∶DOPO=16∶4∶5。燃烧特性、阻燃性能和力学性能等测试、分析结果显示,随TDP/ZnO/DOPO添加量的增大,PC/ABS阻燃复合材料的着火时间(TTI)、热释放速率峰值(PHRR)、总热释放量(THR)、平均有效燃烧热(AEHC)、CO_(2)释放量峰值等燃烧特性数值均下降,阻燃性能(LOI值、UL-94等级)提升,但弯曲强度、拉伸强度均稍有下降。综合考虑,认为较适宜三元协效复合阻燃剂添加量为5%(质量分数),此时,PC/ABS阻燃复合材料的LOI值为28.6%、UL-94等级为V-0级;相较于PC/ABS合金,PC/ABS阻燃复合材料的TTI、PHRR、THR、AEHC、CO_(2)释放量峰值分别下降了27.27%、21.62%、22.10%、5.95%、25.97%,弯曲强度、拉伸强度分别下降了19.65%、13.26%。对三元协效复合阻燃剂的阻燃作用机制进行了初步探讨,认为TDP/ZnO/DOPO对PC/ABS合金的阻燃是DOPO的气相阻燃、TDP和ZnO的凝聚相阻燃两种作用机制协同作用的结果。展开更多
1引言胸腺瘤是一种来源于胸腺上皮细胞的纵隔肿瘤,常见于前纵隔[1]。根据组织学特征,胸腺瘤可分为A型、AB型、B1型、B2型和B3型。其中,AB型胸腺瘤具有A型和B型胸腺瘤的混合特征,在显微镜下可见梭形或椭圆形细胞(A型成分)、少量上皮细胞(...1引言胸腺瘤是一种来源于胸腺上皮细胞的纵隔肿瘤,常见于前纵隔[1]。根据组织学特征,胸腺瘤可分为A型、AB型、B1型、B2型和B3型。其中,AB型胸腺瘤具有A型和B型胸腺瘤的混合特征,在显微镜下可见梭形或椭圆形细胞(A型成分)、少量上皮细胞(B型成分)及不同程度的淋巴细胞浸润[2]。治疗方面,手术切除是首选,尤其适用于局限性病变。对于无法完全切除的肿瘤,放疗和化疗可作为辅助治疗手段[3]。纯红细胞再生障碍性贫血(pure red cell aplasia,PRCA)是一种罕见的获得性骨髓衰竭综合征,主要表现为正细胞正色素性贫血、网织红细胞显著减少及骨髓中红系前体细胞的缺乏或显著减少。其病因复杂,可继发于胸腺瘤、白血病、自身免疫性疾病、病毒感染及药物作用等[4]。展开更多
Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium ...Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium montmorillonite(Na-MMT)(001)surfaces was investigated using first-principles calculations in this study,especially As atom and H_(3)AsO_(3) molecule.The adsorption energies of the As atom were−1.94 eV on the illite(001)and−0.56 eV on the Na-MMT(001),whereas,the adsorption energies of the H_(3)AsO_(3) molecule were−1.40 eV on illite(001)and−1.01 eV on Na-MMT(001).The above results indicate that the adsorption was more energetically favorable on illite(001).Additionally,compared to Na-MMT(001),there were more significant interactions between the atoms/molecules on the illite(001).After As atom and H_(3)AsO_(3) molecule adsorption,the electrons were transferred from mineral surface atoms to the adsorbates on both illite(001)and Na-MMT(001)surfaces.Moreover,the adsorption of As atom on illite(001)and Na-MMT(001)surfaces were more energy favorable compared to Hg,Cd,and Cr atoms.Overall,this work provides new insights into the adsorption behavior of As atoms and As molecules on illite and Na-MMT.The results indicate that illite rich soils are more prone to contamination by arsenic compared to soils primarily composed of Na-MMT minerals.展开更多
This study investigates the potential of metal additives in acrylonitrile butadiene styrene(ABS)polymer fuel to enhance hybrid rocket motor(HRM)performance through computational analysis,Chemical Equilibrium with Appl...This study investigates the potential of metal additives in acrylonitrile butadiene styrene(ABS)polymer fuel to enhance hybrid rocket motor(HRM)performance through computational analysis,Chemical Equilibrium with Applications(CEA),software.ABS was selected as the base fuel due to its thermoplastic nature,which allows for the creation of complex fuel geometries through 3D printing,offering significant flexibility in fuel design.Hybrid rockets,which combine a solid fuel with a liquid oxidiser,offer advantages in terms of operational simplicity and safety.However,conventional polymer fuels often exhibit low regression rates and suboptimal combustion efficiencies.In this research,we evaluated a range of metal additives-aluminium(Al),boron(B),nickel(Ni),copper(Cu),and iron(Fe)-at chamber pressures ranging from 1 to 30 bar and oxidiser-to-fuel(O/F)ratios between 1.1 and 12,resulting in 1800 unique test conditions.The main performance parameters used to assess each formulation were characteristic velocity(C^(*))and adiabatic flame temperature.The results revealed that each test produced a different optimum O/F ratio,with most ratios falling between 4 and 6.The highest performance was achieved at a chamber pressure of 30 bar across all formulations.Among the additives,Al and B demonstrated significant potential for improved combustion performance with increasing metal loadings.In contrast,Fe,Cu,and Ni reached optimal performance at a minimum loading of 1%.Future work includes investigating B-Al metal composites as additives into the ABS base polymer fuel,and doing experimental validation tests where the metallised ABS polymer fuel is 3D printed.展开更多
文摘以废打印机壳PC/ABS再生粒子(R-PC/ABS)为基体材料,对苯二酚双(二苯基磷酸脂)(HDP)和梯形倍半硅氧烷(TSQ)为阻燃剂,采用熔融共混制备了无卤阻燃PC/ABS,对其阻燃性能、力学性能、尺寸稳定性和负荷热变形温度(HDT)进行分析,结果发现,TSQ可以阻燃R-PC/ABS,并且,对力学性能、尺寸稳定性和HDT影响较小,R-PC/ABS/0.8TSQ的LOI为29.8%,阻燃达到3.0 mm V-0和2.0 mm V-1级;HDP可以有效地阻燃R-PC/ABS,但是,对力学性能、尺寸稳定性和HDT的负面影响较大,R-PC/ABS/12HDP的LOI为36.1%,阻燃可达到UL 941.0 mm V-0级,与R-PC/ABS相比,HDT、拉伸强度、弯曲强度、弯曲模量和缺口冲击强度分别降低了20.2℃、26.6%、14.5%、16.9%和60.9%;R-PC/ABS/0.8TSQ/6HDP的LOI为35.7%,阻燃级别达到UL 941.0 mm V-0级,与R-PC/ABS/12HDP相比,模后收缩率(PMS)降低了19.7%,HDT、拉伸强度、弯曲强度、弯曲模量和缺口冲击强度分别提高了13℃、21.0%、11.3%、14.3%和85.9%。
文摘以钛酸四丁酯水解反应原位生成的TiO_(2)包覆微胶囊红磷(microcapsulated red phosphorus,TDP)为主体阻燃剂,开展PC/ABS合金的协效阻燃研究。以PC/ABS阻燃复合材料的LOI值、UL-94等级为主要考察指标,筛选并确定较适宜的TDP基三元协效复合阻燃剂及其质量配比为TDP∶ZnO∶DOPO=16∶4∶5。燃烧特性、阻燃性能和力学性能等测试、分析结果显示,随TDP/ZnO/DOPO添加量的增大,PC/ABS阻燃复合材料的着火时间(TTI)、热释放速率峰值(PHRR)、总热释放量(THR)、平均有效燃烧热(AEHC)、CO_(2)释放量峰值等燃烧特性数值均下降,阻燃性能(LOI值、UL-94等级)提升,但弯曲强度、拉伸强度均稍有下降。综合考虑,认为较适宜三元协效复合阻燃剂添加量为5%(质量分数),此时,PC/ABS阻燃复合材料的LOI值为28.6%、UL-94等级为V-0级;相较于PC/ABS合金,PC/ABS阻燃复合材料的TTI、PHRR、THR、AEHC、CO_(2)释放量峰值分别下降了27.27%、21.62%、22.10%、5.95%、25.97%,弯曲强度、拉伸强度分别下降了19.65%、13.26%。对三元协效复合阻燃剂的阻燃作用机制进行了初步探讨,认为TDP/ZnO/DOPO对PC/ABS合金的阻燃是DOPO的气相阻燃、TDP和ZnO的凝聚相阻燃两种作用机制协同作用的结果。
文摘1引言胸腺瘤是一种来源于胸腺上皮细胞的纵隔肿瘤,常见于前纵隔[1]。根据组织学特征,胸腺瘤可分为A型、AB型、B1型、B2型和B3型。其中,AB型胸腺瘤具有A型和B型胸腺瘤的混合特征,在显微镜下可见梭形或椭圆形细胞(A型成分)、少量上皮细胞(B型成分)及不同程度的淋巴细胞浸润[2]。治疗方面,手术切除是首选,尤其适用于局限性病变。对于无法完全切除的肿瘤,放疗和化疗可作为辅助治疗手段[3]。纯红细胞再生障碍性贫血(pure red cell aplasia,PRCA)是一种罕见的获得性骨髓衰竭综合征,主要表现为正细胞正色素性贫血、网织红细胞显著减少及骨髓中红系前体细胞的缺乏或显著减少。其病因复杂,可继发于胸腺瘤、白血病、自身免疫性疾病、病毒感染及药物作用等[4]。
基金Project(22376221)supported by the National Natural Science Foundation of ChinaProject(2024JJ2074)supported by the Natural Science Foundation of Hunan Province,ChinaProject(2023QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST。
文摘Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium montmorillonite(Na-MMT)(001)surfaces was investigated using first-principles calculations in this study,especially As atom and H_(3)AsO_(3) molecule.The adsorption energies of the As atom were−1.94 eV on the illite(001)and−0.56 eV on the Na-MMT(001),whereas,the adsorption energies of the H_(3)AsO_(3) molecule were−1.40 eV on illite(001)and−1.01 eV on Na-MMT(001).The above results indicate that the adsorption was more energetically favorable on illite(001).Additionally,compared to Na-MMT(001),there were more significant interactions between the atoms/molecules on the illite(001).After As atom and H_(3)AsO_(3) molecule adsorption,the electrons were transferred from mineral surface atoms to the adsorbates on both illite(001)and Na-MMT(001)surfaces.Moreover,the adsorption of As atom on illite(001)and Na-MMT(001)surfaces were more energy favorable compared to Hg,Cd,and Cr atoms.Overall,this work provides new insights into the adsorption behavior of As atoms and As molecules on illite and Na-MMT.The results indicate that illite rich soils are more prone to contamination by arsenic compared to soils primarily composed of Na-MMT minerals.
文摘This study investigates the potential of metal additives in acrylonitrile butadiene styrene(ABS)polymer fuel to enhance hybrid rocket motor(HRM)performance through computational analysis,Chemical Equilibrium with Applications(CEA),software.ABS was selected as the base fuel due to its thermoplastic nature,which allows for the creation of complex fuel geometries through 3D printing,offering significant flexibility in fuel design.Hybrid rockets,which combine a solid fuel with a liquid oxidiser,offer advantages in terms of operational simplicity and safety.However,conventional polymer fuels often exhibit low regression rates and suboptimal combustion efficiencies.In this research,we evaluated a range of metal additives-aluminium(Al),boron(B),nickel(Ni),copper(Cu),and iron(Fe)-at chamber pressures ranging from 1 to 30 bar and oxidiser-to-fuel(O/F)ratios between 1.1 and 12,resulting in 1800 unique test conditions.The main performance parameters used to assess each formulation were characteristic velocity(C^(*))and adiabatic flame temperature.The results revealed that each test produced a different optimum O/F ratio,with most ratios falling between 4 and 6.The highest performance was achieved at a chamber pressure of 30 bar across all formulations.Among the additives,Al and B demonstrated significant potential for improved combustion performance with increasing metal loadings.In contrast,Fe,Cu,and Ni reached optimal performance at a minimum loading of 1%.Future work includes investigating B-Al metal composites as additives into the ABS base polymer fuel,and doing experimental validation tests where the metallised ABS polymer fuel is 3D printed.
