侧链末端为磺酸根基团的磺化改性聚砜的制备及其阳离子交换膜的基本性能

采用两步一锅法,在聚砜(PSF)主链上键联了末端基为磺酸根基团的侧链,获得了疏水主链与磺酸根基团“微相分离”结构的磺化改性PSF。以氯乙基异氰酸酯(CEIC)为亲电试剂,使PSF主链上的苯环发生付-克烷基化反应,制得侧链含有活性基团—NCO的中间产物聚合物PSF-eic;通过活性基团—NCO与对羟基苯磺酸钠(HBSAS)生成氨基甲酸酯的较快速的反应,获得了侧链末端为磺酸根基团的磺化改性聚砜PSF-sas。 采用FT-IR、1H-NMR及紫外分光光度法对目标产物聚合物PSF-sas的化学结构进行了表征。以PSF-sas为膜材,采用流延法制备了PSF阳离子交换膜,测定了交换膜的基本性能,包括离子交换容量、吸水率及质子传导率。研究结果表明,在路易斯酸催化剂作用下,CEIC与PSF主链上苯环之间的付-克烷基化反应可顺利进行,生成中间聚合物产物PSF-eic;以强极性的二甲基乙酰胺(DMAC)为溶剂,反应24 h,PSF-eic分子链中乙基异氰酸酯(eic)的键合量可达2.43 mmol/g。在此基础上进行第2步反应,可得到磺酸根基团含量为2.23 mmol/g的目标产物PSF-sas,所制备的阳离子交换膜,具有高的离子交换容量,适当的吸水率与高的质子传导率。     

Co3O4–Ag photocatalysts for the efficient degradation of methyl orange

In this paper, a series of Co₃O₄–Ag photocatalysts with different Ag loadings were synthesized by facile hydrothermal and in situ photoreduction methods and fully characterized by XRD, SEM, TEM, FTIR spectroscopy, XPS, UV-vis and PL techniques. The catalysts were used for the degradation of methyl orange (MO). Compared with the pure Co₃O₄ catalyst, the Co₃O₄–Ag catalysts showed better activity; among these, the Co₃O₄–Ag-0.3 catalyst demonstrated the most efficient activity with 96.4% degradation efficiency after 30 h UV light irradiation and high degradation efficiency of 99.1% after 6 h visible light irradiation. According to the corresponding dynamics study under UV light irradiation, the photocatalytic efficiency of Co₃O₄–Ag-0.3 was 2.72 times higher than that of Co₃O₄ under identical reaction conditions. The excellent photocatalytic activity of Co₃O₄–Ag can be attributed to the synergistic effect of strong absorption under UV and visible light, reduced photoelectron and hole recombination rate, and decreased band gap due to Ag doping. Additionally, a possible reaction mechanism over the Co₃O₄–Ag photocatalysts was proposed and explained.

A novel Co₃O₄–Ag catalyst covered on the Ni foam substrate was synthesized via facile hydrothermal and in situ photoreduction methods for the efficient degradation of methyl orange.     

大学生情绪智力与心理健康的关系

目的了解大学生情绪智力与心理健康状况之间的关系,为大学生心理健康咨询与教育提供科学依据。方法采用情绪智力量表(EIS)和症状自评量表(SCL-90),对整群随机抽取的太原市312名大学生进行问卷调查。结果大学生人际敏感因子的城乡差异有统计学意义;SCL-90总分及各因子(除躯体化、焦虑、恐怖)的年级差异有统计学意义。大学生情绪智力总分与SCL-90总分及抑郁、恐怖、偏执、精神病性显著负相关,情绪自控能力与调控他人情绪能力与SCL-90总分及大部分因子显著负相关。除强迫、敌对外,不同情绪智力水平大学生SCL-90总分及各因子差异有统计学意义。情绪自控能力进入了大学生总体心理健康及各因子的回归模型中,情绪自控能力联合运用情绪能力能有效预测大学生总体心理健康及大部分因子。结论自我调控能力和运用情绪能力是大学生心理健康的重要预测指标。     

Experimental and theoretical study for CO2 activation and chemical fixation with epoxides

The synthesis of five-membered cyclic carbonates via catalytic cycloaddition reaction of CO₂ with epoxides is considered to be an effective technology for alleviation of the energy crisis and global warming. Various commercial organic bases and ionic salts were used as catalysts, while the relationship of catalytic activity and compound structure has been seldom explored. Herein, a facilely obtained binary catalytic system based on triethylamine/NBu₄Br was developed for CO₂ activation and chemical fixation. The highly efficient catalytic system showed outstanding conversion and above 99% selectivity under metal-free mild reaction conditions (100 °C, 1 atm) in one hour. The detailed process of CO₂ activation and chemical fixation was investigated at the molecular level by a series of experiments and theoretical calculation, which provided a mode for the design and synthesis of a highly efficient catalytic system for conversion of CO₂ under mild conditions.

NEt₃/NBu₄Br works as an excellent metal-free catalyst for CO₂ cycloaddition with epoxides and the detailed process of CO₂ activation by NEt₃ is first studied by theoretical calculation.     

一定条件下电压信号与血清蛋白浓度的关系

背景：蛋白质的定量测定在各个领域中有着重要的意义。目的：探讨血清蛋白浓度与共振散射光强度的关系。方法：以405nm的激发光波照射在四羧基酞菁锌与血清蛋白混合溶液上,共振散射光在475nm处强度最强,Si-PIN光电探测器把475nm的出射光信号转换成电压信号。结果与结论：实验结果表明,2.0×10-4mol/L四羧基酞菁锌与血清蛋白混合溶液的实验数据在10～50g/L范围内线性关系良好,相关系数r=0.9939,结果满意。     

MRI/fluorescence dual-mode probe: its simple preparation method and imaging application in vitro

Superparamagnetic nanoparticles have been widely used as contrast agents in magnetic resonance imaging (MRI). The combined use of multiple imaging modes can provide more accurate information for clinical diagnosis. In this paper, a MRI/fluorescence dual-mode imaging contrast agent was developed by a simple method. The method is to make the fluorescent carbon quantum dots (CDs) adsorbed on the surface of the magnetic composite with pore structure by ultrasonic dispersion. Replacing the traditional methods such as chemical bonding, the fluorescent material is coated on the surface of the composite material. The synthesized composite materials were characterized by the transmission electron microscopy method (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and vibration sample magnetometer (VSM). The results of TEM, FTIR and XPS showed that CDs were successfully coated on the surface of C₆₀@Fe₃O₄ magnetic composite. The VSM results show that the composite material still maintains superparamagnetism. The cytotoxicity of the material on SMMC-7721 liver cancer cells was detected by the MTT method, and the biocompatibility of the material was verified. By observing the fluorescence distribution in the cell, it is proved that the composite material successfully enters the cell and produces fluorescence. Finally, through the analysis of T₂-weighted imaging, it is found that the addition of materials results in an enhanced dark contrast compared to control cells. Therefore, the composite nanomaterials synthesized in this paper can be used as MRI/fluorescence dual-mode imaging contrast agents.     

Optimization of the electrodeposition process of a polypyrrole/multi-walled carbon nanotube fiber electrode for a flexible supercapacitor

In the large-scale production of flexible supercapacitors, given the poor interface stability and the low mass loading of functional films on the fiber electrode, cyclic voltammetry (CV) and constant current (CC) electrodeposition methods were adopted to prepare polypyrrole/multi-walled carbon nanotubes (PPy/MWCNTs) on the surface of polyacrylonitrile (PAN) carbon cloth to explore the optimization process. The surface morphology and structural properties of the flexible electrode were characterized, and the electrical and electrochemical properties were studied. The research indicated that the PPy/MWCNTs were uniformly distributed on the fiber surface in the form of a linear structure and were amorphous and rich in carbon, nitrogen, and oxygen functional groups. A higher deposition current density helped improve the degree of coating of the MWCNTs with PPy and the number of oxygen-containing functional groups. The electrical and electrochemical properties of the flexible electrode prepared using the CC method were excellent; the electrochemical properties of the samples in the bent state were not significantly different from those in the straightened state. Using CC and CV methods, the conductivities of the samples were 32.4 S cm⁻¹ and 24.1 S cm⁻¹, the area-specific capacitance values were C 96.24 mF cm⁻² and 46.18 mF cm⁻² at a scan rate of 100 mV s⁻¹, the equivalent series resistance R_s values were 2.74 Ω and 4.67 Ω, the specific capacitance retention rates were 94.4% and 88.3% after 1000 cycles, and the capacitance retention rates were 89.7% and 80.6% after 5000 cycles, respectively. The differences in the performances of the flexible electrodes using the same preparation solvent and different preparation processes were due to the higher deposition current density of the CC method compared with that of CV. The former enhanced the polymerization degree of the PPy/MWCNT flexible electrode and improved the electrochemical performance. The presented research results are significant for the optimization of large-scale production processes.

The difference between the electrical and electrochemical properties of PPy/MWCNTs flexible electrodes was found to be due to the constant current method having a higher deposition current density, leading to a higher degree of polymerization.     

基于工业CT断层图像的三维可视化

工业CT图像三维可视化能够对工业构件提供真实、直观的反映。体绘制技术可以显示工业CT三维数据的整体特征和内部细节信息。根据光线投射算法的特点，采用对原始数据场进行最大熵原则的预处理的方法，加快了绘制速度，在一定程度上改进了光线投射算法，取得了较好的显示效果。     

一种基于笔形束核的快速剂量计算方法

针对传统笔形束核剂量算法计算过程复杂、速度较慢的问题,提出一种基于笔形束核的快速剂量计算方法。该方法在球壳坐标系下,利用射束与不同球壳层碰撞后轴线与体素相交情况的相似性,通过对每条射束只计算初始球壳层碰撞点处轴线与体素的相交情况,并将初始球壳层深度与其它球壳层深度的比值作为校正因子得到其他层碰撞点处轴线与体素的相交情况。避免射线追踪法的重复使用,在不影响算法精度的情况下节省大量时间。实验结果表明:在不同射野大小［（3×3）、（5×5）、（10×10） cm2］的水模体中计算深度剂量分布,两种算法的计算精度基本一致,改进算法的计算速度提升约2.7倍。同时当射野面积为（10×10） cm2时,在肺阻块模体和骨阻块模体不同深度的剖面剂量计算中,改进算法与传统算法的计算精度也基本一致,但计算速度提升约2.6倍。