The novel magnetic sepiolite/Fe_(3)O_(4)/zero-valent iron(nZVI)nanocomposite(nZVI@SepH-Mag)was prepared and used to achieve the removal of Cr(VI)in this work.The nZVI@SepH-Mag composites were characterized by XRD,FTIR...The novel magnetic sepiolite/Fe_(3)O_(4)/zero-valent iron(nZVI)nanocomposite(nZVI@SepH-Mag)was prepared and used to achieve the removal of Cr(VI)in this work.The nZVI@SepH-Mag composites were characterized by XRD,FTIR,BET,SEM and TEM.The characterization results indicated that the structure of the composite consisted of small nanoscale nZVI and magnetite(Mag)particles uniformly anchoring on the surface of acid-activated sepiolite(SepH).Batch experiments were used to analyze the effects of main factors on Cr(VI)removal.A 100%removal efficiency in 60 min and enhanced reaction ratio were reached by the composite comparing other existing materials.The kinetic of the adsorption and possible Cr(VI)removal mechanism of the hybrids were also evaluated and proposed.Based on the removal products identified by Raman,XRD and XPS,a reduction mechanism was proposed.The results indicated that the SepH and Mag can inhibit the agglomeration and enhance the dispersibility of nZVI,and Mag and nZVI displayed good synergetic effects.展开更多
利用电化学法在不锈钢网上直接生长出了墨绿色、高比电容、光敏性的双功能聚苯胺薄膜,从而完全省略了加大电阻的黏结剂。采用紫外吸收光谱、扫描电子显微镜(scanning electron microscope,SEM)、循环伏安法(cyclic voltammetry,CV)、恒...利用电化学法在不锈钢网上直接生长出了墨绿色、高比电容、光敏性的双功能聚苯胺薄膜,从而完全省略了加大电阻的黏结剂。采用紫外吸收光谱、扫描电子显微镜(scanning electron microscope,SEM)、循环伏安法(cyclic voltammetry,CV)、恒电流充放电(galvanostatic charge/discharge,GCD)及阻抗分析法(electrical impedance spectroscopy,EIS)等方法对样品进行表征和测试,并且在不同的测试条件下对电容进行了统计和比较。在3种网状结构的聚苯胺中,最疏松的聚苯胺网络具有最大的比电容(443.7F/g)和最高的导电性(44S/cm)。这是由于疏松的网状结构材料可以充分地与电解液接触,提高了聚苯胺薄膜的比电容。同时,该聚苯胺薄膜具有很好的光敏性质,对白光有最强的光电响应,可以作为光敏传感器。展开更多
为了降低三相LCL型并网逆变器中高次谐波和网侧背景谐波对并网电流电能质量的影响,提出了一种基于滑动平均滤波器的多谐振(multi resonance based on moving average filter,MR-MAF)控制器。首先根据滑动平均滤波器的频域特性设计控制器...为了降低三相LCL型并网逆变器中高次谐波和网侧背景谐波对并网电流电能质量的影响,提出了一种基于滑动平均滤波器的多谐振(multi resonance based on moving average filter,MR-MAF)控制器。首先根据滑动平均滤波器的频域特性设计控制器,使其具有近似比例积分多谐振控制器的结构,实现谐波抑制。然后,引入2个可调系数,对该控制器控制性能进行灵活调整。最后,通过仿真和样机实验,验证了所提MR-MAF控制器在谐波抑制和提高电能质量方面的有效性。结果表明,与经典的比例积分多谐振控制器相比,本文提出的控制器不仅可以在保持相同动态性能的情况下并联多个谐振项,而且稳态性能更优,谐波含量由6.8%降至4%。因此,本文所提控制器具有结构简单且抑制谐波频带范围宽的特点,可为改善三相并网逆变器在多谐波环境下的控制性能提供参考。展开更多
目的 本研究旨在探讨细胞外基质刚度变化对神经干细胞(neural stem cells,NSCs)分化的影响及其作用机制。方法 本研究基于成功构建脊髓损伤大鼠模型,并制备不同刚度(0.7 k Pa、40 k Pa)的聚丙烯酰胺凝胶基底,将大鼠原代NSCs于不同刚度...目的 本研究旨在探讨细胞外基质刚度变化对神经干细胞(neural stem cells,NSCs)分化的影响及其作用机制。方法 本研究基于成功构建脊髓损伤大鼠模型,并制备不同刚度(0.7 k Pa、40 k Pa)的聚丙烯酰胺凝胶基底,将大鼠原代NSCs于不同刚度基底上培养。压电型机械敏感离子通道组件1 (piezo type mechanosensitive ion channel component 1,Piezo1) sh RNA质粒转染NSCs细胞。免疫荧光染色检测神经元标志物双皮质醇(doublecortion,DCX)和星形胶质细胞标志物胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)阳性细胞百分比。免疫组织化学及蛋白质免疫印迹(Western blot)法检测损伤组织及NSCs细胞中Piezo1蛋白的表达水平。结果 与0.7 k Pa基质刚度组相比,40 k Pa基质刚度组中DCX阳性细胞数增加,而GFAP阳性细胞数减少,Piezo1蛋白表达量上升。脊髓损伤大鼠损伤组织Piezo1蛋白表达显著高于空白对照(sham)组。40 k Pa基质刚度条件下沉默Piezo1后,DCX阳性细胞数减少,而GFAP阳性细胞数增加,差异具有统计学意义(P<0.05)。机制研究发现,沉默Piezo1导致IV型胶原及纤连蛋白表达下降。重组纤连蛋白逆转了Piezo1 sh RNA对NSCs分化的影响,即DCX阳性细胞数增加,而GFAP阳性细胞数减少。结论 综上可见,硬基底刚度通过促进Piezo1蛋白表达,上调IV型胶原及纤连蛋白表达,从而调控NSCs细胞分化。本研究为基于生物材料治疗脊髓损伤提供了新的视角。展开更多
基金Projects(52474138,52104261,52525401)supported by the National Natural Science Foundation of ChinaProject supported by the New Cornerstone Science Foundation through the XPLORER PRIZE,ChinaProject supported by the Shanxi Key Laboratory Funds of Mine Rock Strata Control and Disaster Prevention,China。
文摘The novel magnetic sepiolite/Fe_(3)O_(4)/zero-valent iron(nZVI)nanocomposite(nZVI@SepH-Mag)was prepared and used to achieve the removal of Cr(VI)in this work.The nZVI@SepH-Mag composites were characterized by XRD,FTIR,BET,SEM and TEM.The characterization results indicated that the structure of the composite consisted of small nanoscale nZVI and magnetite(Mag)particles uniformly anchoring on the surface of acid-activated sepiolite(SepH).Batch experiments were used to analyze the effects of main factors on Cr(VI)removal.A 100%removal efficiency in 60 min and enhanced reaction ratio were reached by the composite comparing other existing materials.The kinetic of the adsorption and possible Cr(VI)removal mechanism of the hybrids were also evaluated and proposed.Based on the removal products identified by Raman,XRD and XPS,a reduction mechanism was proposed.The results indicated that the SepH and Mag can inhibit the agglomeration and enhance the dispersibility of nZVI,and Mag and nZVI displayed good synergetic effects.
文摘为了降低三相LCL型并网逆变器中高次谐波和网侧背景谐波对并网电流电能质量的影响,提出了一种基于滑动平均滤波器的多谐振(multi resonance based on moving average filter,MR-MAF)控制器。首先根据滑动平均滤波器的频域特性设计控制器,使其具有近似比例积分多谐振控制器的结构,实现谐波抑制。然后,引入2个可调系数,对该控制器控制性能进行灵活调整。最后,通过仿真和样机实验,验证了所提MR-MAF控制器在谐波抑制和提高电能质量方面的有效性。结果表明,与经典的比例积分多谐振控制器相比,本文提出的控制器不仅可以在保持相同动态性能的情况下并联多个谐振项,而且稳态性能更优,谐波含量由6.8%降至4%。因此,本文所提控制器具有结构简单且抑制谐波频带范围宽的特点,可为改善三相并网逆变器在多谐波环境下的控制性能提供参考。
文摘目的 本研究旨在探讨细胞外基质刚度变化对神经干细胞(neural stem cells,NSCs)分化的影响及其作用机制。方法 本研究基于成功构建脊髓损伤大鼠模型,并制备不同刚度(0.7 k Pa、40 k Pa)的聚丙烯酰胺凝胶基底,将大鼠原代NSCs于不同刚度基底上培养。压电型机械敏感离子通道组件1 (piezo type mechanosensitive ion channel component 1,Piezo1) sh RNA质粒转染NSCs细胞。免疫荧光染色检测神经元标志物双皮质醇(doublecortion,DCX)和星形胶质细胞标志物胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)阳性细胞百分比。免疫组织化学及蛋白质免疫印迹(Western blot)法检测损伤组织及NSCs细胞中Piezo1蛋白的表达水平。结果 与0.7 k Pa基质刚度组相比,40 k Pa基质刚度组中DCX阳性细胞数增加,而GFAP阳性细胞数减少,Piezo1蛋白表达量上升。脊髓损伤大鼠损伤组织Piezo1蛋白表达显著高于空白对照(sham)组。40 k Pa基质刚度条件下沉默Piezo1后,DCX阳性细胞数减少,而GFAP阳性细胞数增加,差异具有统计学意义(P<0.05)。机制研究发现,沉默Piezo1导致IV型胶原及纤连蛋白表达下降。重组纤连蛋白逆转了Piezo1 sh RNA对NSCs分化的影响,即DCX阳性细胞数增加,而GFAP阳性细胞数减少。结论 综上可见,硬基底刚度通过促进Piezo1蛋白表达,上调IV型胶原及纤连蛋白表达,从而调控NSCs细胞分化。本研究为基于生物材料治疗脊髓损伤提供了新的视角。
