Investigating bottom-quark Yukawa interaction at Higgs factory

Measuring the fermion Yukawa coupling constants is important for understanding the origin of the fermion masses and their relationship with spontaneously electroweak symmetry breaking.In contrast,some new physics(NP)models change the Lorentz structure of the Yukawa interactions between standard model(SM)fermions and the SM-like Higgs boson,even in their decoupling limit.Thus,the precise measurement of the fermion Yukawa interactions is a powerful tool of NP searching in the decoupling limit.In this work,we show the possibility of investigating the Lorentz structure of the bottom-quark Yukawa interaction with the 125 GeV SM-like Higgs boson for future e^+e^- colliders.     

Electrochemical characteristics of a platinum electrode modified with a matrix of polyvinyl butyral and colloidal Ag containing immobilized horseradish peroxidase

A new hydrogen peroxide biosensor was constructed, which consisted of a platinum electrode modified by a matrix of polyvinyl butyral (PVB) and nanometer-sized Ag colloid containing immobilized horseradish peroxidase (HRP), and using Co(bpy)₃³⁺ as mediator in the hydrogen peroxide solution. The electrochemical characteristics of the biosensor were studied by cyclic voltammetry and chronoamperometry. The modified process was characterized by electrochemical impedance spectroscopy and cyclic voltammetry. The HRP immobilized on colloidal Ag was stable and retained its biological activity. The sensor displays excellent electrocatalytic response to the reduction of H₂O₂. Analytical parameters such as pH and temperature were also studied. Linear calibration for H₂O₂ was obtained in the range of 1×10^–5 to 1×10^–2 M under optimized conditions. The sensor was highly sensitive to H₂O₂, with a detection limit of 2×10^–6 M, and the sensor achieved 95% of steady-state current within 10 s. The sensor exhibited high sensitivity, selectivity and stability.     

用多官能团引发剂合成超支化聚苯乙烯及其C60衍生物

通过α-溴丙酰溴与Z5(季戊四醇与2,2-二羟甲基丙酸缩聚的产物)酯化反应制得超支化原子转移自由基聚合(ATRP)引发剂Z5-B(约含19个引发点).在100℃及CuCl/N,N,N,N",N"-五甲基二亚乙基三胺催化下,用Z5-B引发苯乙烯的ATRP聚合(环己酮为溶剂,体积分数为50%),得到超支化的聚苯乙烯,将溴端基叠氮化后与C60反应,获得超支化聚苯乙烯C60衍生物.该超支化C60衍生物可用于光限制材料.     

高效液相色谱-电感耦合等离子体质谱联用测定生物样品中无机汞和甲基汞

建立了高效液相色谱(HPLC)和电感耦合等离子体质谱(ICP-MS)联用测定多种生物样品中的无机汞和甲基汞的方法,并对比了提取生物样品中无机汞和甲基汞的不同前处理方法。实验使用5 mol/L的盐酸超声波提取样品中的无机汞和甲基汞。高效液相色谱流动相为含有0.06 mol/L醋酸氨,20μg/L B i,0.1%(V/V)2-巯基乙醇的5%(V/V)甲醇-水溶液,色谱柱为C18反相柱(5μm,3.9 mm×150 mm)。提取液在液相色谱中分离后,进入电感耦合等离子体质谱检测其中无机汞和甲基汞的浓度。测定了人发(GBW 07601),对虾(GBW 08572),鱼肉组织(IAEA MA-B-3/TM)和牛肝(GBW 080193)4种生物标准参考物,结果与标准参考物的标准值相符。无机汞和甲基汞检出限分别为0.3和0.2μg/L。     

基于双氨基三唑硫醚为中性载体的汞离子选择性电极的研究

研制了基于双氨基三唑硫醚为中性载体的阳离子选择性电极。实验表明,该电极对Hg2 具有良好的电位响应特性,在pH 2.0硝酸盐缓冲液中,电极电位呈近能斯特响应,线性响应范围为4.0 mg/L~20 g/L,斜率为33.4 mV/dec.(25℃),检出限为1.7 mg/L。该电极响应时间短(<10 s),pH范围较宽(1.3~3.3)。将该电极用于实际水样和二元混合溶液中Hg2 的检测,其结果令人满意。     

Ce1-XMnXO2-a复合氧化物催化剂甲烷催化燃烧性能的研究

采用水热法合成了系列Ce_1-XMn_XO_2-a-T(X=0.0，0.1，0.2，0.3，0.5，0.7，0.9，1.0；T表示焙烧温度)，T=500，650，800 ℃)复合氧化物催化剂用于甲烷的催化燃烧。通过XRD、N₂吸/脱附、TG-DSC、UV-Vis-DRS和TPR表征手段研究了不同组成催化剂的物理化学性质及其对甲烷催化燃烧活性。结果表明，在500 ℃焙烧的情况下Mn进入CeO₂晶格形成均相固溶体催化剂的最大取代值为0.7，而当Mn继续增加时则出现Mn₂O₃晶相偏析，同时各催化剂具有较高的比表面积；随着焙烧温度的升高，进入CeO₂晶格的Mn最大取代值逐渐减少，650和800 ℃时分别为0.5和0.3，且比表面积相应降低。Ce_1-XMn_XO_2-a-800催化剂的还原行为大致呈现三阶段，即为Mn₂O₃ → Mn₃O₄的还原(340～420 ℃)，Mn₃O₄ → MnO的还原(420～480 ℃)和体相氧化铈的还原(700～900 ℃)，且Mn的引入整体上提高了催化剂的可还原能力。甲烷催化燃烧活性评价结果表明，比表面积并非影响催化剂活性的主要因素，影响催化剂甲烷催化活性的主要因素为催化剂的组成、可还原能力和焙烧温度；而其中以Ce_0.3Mn_0.7O_2-a-800催化剂表现出较高的甲烷催化燃烧活性，在甲烷转化率为10%和90%时的温度分别为430 和613 ℃。进一步考察Ce_0.3Mn_0.7O_2-a在不同温度(500、650、800和1 000 ℃)焙烧后的催化活性表明，随着焙烧温度的提高催化剂催化活性降低。     

Highly sensitive luminol electrochemiluminescence immunosensor based on ZnO nanoparticles and glucose oxidase decorated graphene for cancer biomarker detection

In this work, we reported a sandwiched luminol electrochemiluminescence (ECL) immunosensor using ZnO nanoparticles (ZnONPs) and glucose oxidase (GOD) decorated graphene as labels and in situ generated hydrogen peroxide as coreactant. In order to construct the base of the immunosensor, a hybrid architecture of Au nanoparticles and graphene by reduction of HAuCl₄ and graphene oxide (GO) with ascorbic acid was prepared. The resulted hybrid architecture modified electrode provided an excellent platform for immobilization of antibody with good bioactivity and stability. Then, ZnONPs and GOD functionalized graphene labeled secondary antibody was designed for fabricating a novel sandwiched ECL immunosensor. Enhanced sensitivity was obtained by in situ generating hydrogen peroxide with glucose oxidase and the catalysis of ZnONPs to the ECL reaction of luminol–H₂O₂ system. The as-prepared ECL immunosensor exhibited excellent analytical property for the detection of carcinoembryonic antigen (CEA) in the range from 10 pg mL⁻¹ to 80 ng mL⁻¹ and with a detection limit of 3.3 pg mL⁻¹ (S N⁻¹ = 3). The amplification strategy performed good promise for clinical application of screening of cancer biomarkers.     

SiO_2-CeO_2复合氧化物对硅片的抛光性能评价

用合成的S iO2-CeO2复合氧化物对单晶硅片进行抛光,测定其抛光速率与制备条件及浆料配制条件之间的关系。结果表明:经800℃煅烧后制得的硅铈摩尔比nS iO2∶nCeO2为2∶1的复合氧化物对硅片具有最大的抛蚀速率。与此同时,选用三乙醇胺和六偏磷酸钠分别作为浆料的pH调节剂和分散剂可以获得理想的浆料分散性和悬浮稳定性。确定了抛光浆料的最佳pH值和固含量分别为11和4%。     

A novel electrochemical aptasensor for highly sensitive detection of thrombin based on the autonomous assembly of hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme nanowires

In this work, a new signal amplified strategy was constructed based on isothermal exponential amplification reaction (EXPAR) and hybridization chain reaction (HCR) generating the hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme (HRP-mimicking DNAzyme) nanowires as signal output component for the sensitive detection of thrombin (TB). We employed EXPAR’s ultra-high amplification efficiency to produce a large amount of two hairpin helper DNAs within a minutes. And then the resultant two hairpin helper DNAs could autonomously assemble the hemin/G-quadruplex HRP-mimicking DNAzymes nanowires as the redox-active reporter units on the electrode surface via hybridization chain reaction (HCR). The hemin/G-quadruplex structures simultaneously served as electron transfer medium and electrocatalyst to amplify the signal in the presence of H₂O₂. Specifically, only when the EXPAR reaction process has occurred, the HCR could be achieved and the hemin/G-quadruplex complexes could be formed on the surface of an electrode to give a detectable signal. The proposed strategy combines the amplification power of the EXPAR, HCR, and the inherent high sensitivity of the electrochemical detection. With such design, the proposed assay showed a good linear relationship within the range of 0.1 pM–50 nM with a detection limit of 33 fM (defined as S/N = 3) for TB.     

两性霉素B与鞘磷脂单分子层的相互作用

选取哺乳动物生物膜中的重要脂质分子鞘磷脂(SM)作为单分子膜的基本组分, 采用Langmuir-Blodgett(LB)膜技术研究了不同比例的两性霉素B/鞘磷脂单层膜的表面压力-平均分子面积(π-A)曲线以及基于π-A曲线的混合性分析, 同时通过原子力显微镜(AFM)研究了其表面形态的变化. 结果表明, 组分间的摩尔比和表面压力对混合单层膜稳定性、混合性以及分子间相互作用具有重要影响.