温度对脱硫剂钙利用率和蒸汽活化效果的影响

在中温烟气脱硫过程中,蒸汽活化对于提高脱硫剂的钙利用率和脱硫效率起到了显著的作用。为了确定温度对于蒸汽活化效果的影响,研究了200～800℃的蒸汽温度范围内钙利用率的变化,给出了合适的蒸汽活化温度。进而分别在400、600、800℃条件下研究了脱硫反应温度与蒸汽活化温度的关系,提出了中温循环流化床烟气脱硫的适用温度范围。     

A Novel Frequency Measurement Method Suitable for a Large Frequency Ratio Condition

As for the obstacles to direct comparison between superhigh and lower frequencies, we accomplish the accurate comparison between low and microwave frequencies with the 10^5 ratios of the operating frequencies on the basis of phase comparison between the signals whose frequencies are related by an arbitrary integer. This method is simple and accurate, and will be widely used as a special frequency comparison approach.     

Ab-Initio Study of Electronic Structure and Magnetic Properties of Pipz-H2 [MnF4（HF2）]

The full-potential linearized augmented plane wave method was applied to study the electronic and the magnetic properties of the compound pipz-H2[MnF4(HF2)](pipz=piperazine). The band structure, the total density of states, the partial density of states and the electron density were calculated to explain the electronic and the magnetic properties of pipz-H2[MnF4(HF2)] in the ferromagnetic state. It is found that the magnetic moment of the molecule mainly comes from the Mn atoms with partial contribution from the F atoms. The symmetrical σ/σ bonds via H atoms along Mn-F-H-F-Mn chains and the weak direct-exchange interaction between F(2), F(3) and Mn atoms have effect on the electronic structure and the magnetism of pipz-H2 [MnF4(HF2)].     

柔性透明导电薄膜(ITO)简介

柔性透明导电薄膜 (ＩＴＯ)是一种新型半导体材料 ,目前主要依赖进口 ,但价格昴贵 ,国内生产厂家较少。深圳市北庆薄膜技术有限公司经多年研制、开发 ,形成了年产 50 ,0 0 0ｍ2 透明导电膜 (ＩＴＯ)的能力 ,产品质量完全可以替代同类进口产品。北庆公司所生产的导电膜具有重量轻、体薄、导电性能好、附着力强、透过率高、耐冲击、可弯曲、可任意冲裁加工等优点。该产品可以用作光电子器件的透明电极、电磁静电屏蔽的透明视窗、观察窗以及防霜加热膜 ,还可以用在特殊要求的透明器件上作防静电包装。在某些方面它可以取代导电玻璃 ,并且可以开…     

单参数非线性问题中高阶奇异点的计算

本文考虑计算单参数非线性问题中高阶奇异点的数值方法，基于确定奇异点的一个普适的扩张系统，结合同伦参数的拟弧长延拓，给出了计算各类高阶奇异点的一个统一算法，数值例子表明了算法的有效性．     

对2020年全国新高考Ⅰ卷第21题的解法探究

通过六种方法对2020年全国新高考Ⅰ卷第21题进行多维度的试题分析、解法探究、变式训练,旨在全面阐释这类题目的解题策略.     

Diethanol ammonium-borate based polybetaine with tunable UCST phase transition

A betaine-type styrene monomer with the quaternary ammonium-borate anion inner-salt pair was synthesized through the quaternization reaction and polymerized to afford the target polybetaine of poly(4-vinylbenzyl methyl-diethanol ammonium borate)(PVMAB). The chemical structures of the monomer and polymer were well demonstrated with ~1H-NMR and ~(11)B-NMR spectra analysis. The thermal-sensitive experiment showed that PVMAB in water afforded gradually welldefined sigmoidal transmittance-temperature(T-t) curves along with the increasing polymer concentration. However, the phase transition temperatures at the bottom of the S-shaped curves were always below 10 ℃ due to the very weak zwitterionic association of the ammonium-borate inner-salt pairs. The UCST phase transition could also be tuned by changing the ethanol content in the ethanol/water mixture. And the cytotoxicity experiment demonstrated the good biomimetic property of PVMAB. This study enriches the toolbox of polybetaines by introducing the quaternary ammoniumborate anion zwitterionic pair in the repeat units, therefore broadens the scope of synthetic polybetaines.     

基于单细胞拉曼光谱技术的葡萄球菌黄素生物合成分析

利用光镊拉曼光谱技术研究吲哚对金葡菌细胞中葡萄球菌黄素合成的抑制作用以及色素含量在分批培养过程中的动态变化。收集经不同浓度吲哚(终浓度为0,0.2,0.6,0.8,1.2和1.5 mmol/L)处理后的以及不同培养时间的金葡菌单细胞的拉曼光谱,以光谱1523 cm-1峰强度表征色素含量,并与紫外可见分光光度法得到的结果进行比较。结果表明,细菌拉曼光谱1523 cm-1峰强度与分光光度法测得的色素含量有良好的线性关系,相关系数达0.9772;群体和单细胞水平的光谱数据均表明,吲哚可剂量依赖性地抑制葡萄球菌黄素的合成,色素含量降低幅度超过70%;在分批培养中细菌色素含量在对数生长中期(12 h)达到最大值,各个时间点的群体内部细胞间色素含量的异质性较小,RSD在39.2%~61.1%之间。本研究表明光镊拉曼光谱技术是一种在单细胞水平分析葡萄球菌黄素含量的可靠方法。     

乙酸/三氟化硼乙醚混合电解质中咔唑的电化学聚合

在新型混合电解质——乙酸含体积比26%的三氟化硼乙醚和5%的分子量为400的聚乙二醇中直接氧化咔唑制得高质量的聚咔唑膜,导电率为10-2 S·cm-1。在该体系中,咔唑的起始氧化电位相对于饱和甘汞电极只有0.89 V,远低于在含0.1 mol·L-1四氟化硼四丁基铵的乙腈溶液中的1.36V（相对于饱和甘汞电极）。从该体系中获得的聚咔唑膜具有良好的电化学性质和热稳定性,可以部分溶于二甲基亚砜、四氢呋喃等强极性溶剂。荧光光谱表明该体系中获得的聚咔唑膜是一种良好的蓝光发射材料。红外、核磁波谱和理论量子化学计算结果表明,咔唑的电化学聚合主要发生在3,6位。据我们所知,这是利用乙酸三氟化硼乙醚混合电解质进行电化学聚合的首次报道。     

超高效液相色谱-电雾式检测器测定福建产绞股蓝中绞股蓝皂苷XLVI和LVI北大核心CSCD

该研究利用超高效液相色谱-电雾式检测器(UHPLC-CAD)建立了福建产绞股蓝中绞股蓝皂苷XLVI和LVI含量的测定方法。首先利用超高效液相色谱-四极杆-飞行时间质谱(UHPLC-Q-TOF/MS)结合UHPLC-CAD鉴定了福建产绞股蓝的主要成分,其中绞股蓝皂苷XLVI、LVI以及二者相应的含丙二酰基酸性皂苷为其主成分,因此在含量测定时先进行碱水解预处理将酸性皂苷转化为对应的去丙二酰基中性皂苷,再利用UHPLC-CAD测定碱水解后绞股蓝皂苷XLVI和LVI的含量。将绞股蓝样品粉末在乙醇-水-氨水(50∶46∶4,v/v/v)和料液比1∶150(g∶mL)条件下超声提取30 min,静置24 h后,在Waters ACQUITY UPLC BEH C18色谱柱(100 mm×2.1 mm,1.7μm)上分离,采用0.1%(v/v)甲酸水溶液和乙腈作为流动相进行梯度洗脱,流速0.5 mL/min,柱温40℃,电雾式检测器检测。结果表明,绞股蓝皂苷XLVI和LVI分别在9.94~318.00μg/mL和12.78~409.00μg/mL范围内具有良好的线性关系,相关系数(r)分别为0.9993和0.9995。方法精密度、重复性和24 h稳定性试验的相对标准偏差(RSD)均小于2.0%(n=6),绞股蓝皂苷XLVI与LVI的加标回收率分别在100.2%~107.2%与97.9%~104.2%范围内,RSD值分别为2.4%与2.6%。16批绞股蓝样品含量测定结果显示:绞股蓝皂苷XLVI含量占0.57%~2.57%,绞股蓝皂苷LVI含量占0.66%~2.99%。该方法灵敏度高,重复性好,可用于福建产绞股蓝的质量研究和质量控制。