低压离子色谱法在酸雨分析中的应用

低压离子色谱是作者提出的一种新的分析法，可以在１．９６～２．９４×１０＾５Ｐａ低压分析碱金属，碱土金属，过渡金属阳离子，无机阴离子及许多有机酸离子，本文用低压离子色谱法分析了成都地区酸雨中Ｎａ，ＮＨ４，Ｋ＾＋，Ｍｇ＾２＋，Ｃａ＾２＋，Ｆ＾－，Ｃｌ＾－，ＮＯ３＾－，ＳＯ＾２－４等离子，获得了满意的结果。     

九配位钬-三乙四胺六乙酸配合物K3[Ho(TIHA)]·5H2O的合成及分子结构

稀土金属离子氨基多羧酸配合物由于其配位数和结构的多样性,多年来一直是化学家们所感兴趣的内容之一[1-3].例如Sakagami N.等人就曾对稀土金属离子氨基多羧酸配合物做了系统的研究[4],总结出La(Ⅲ)-EDTA形成十配位结构配合物,Ln(Ⅲ)-EDTA(Ln(Ⅲ)指Pr(Ⅲ),Nd(Ⅲ),Sm(Ⅲ),Eu(Ⅲ),Gd(Ⅲ),Dv(Ⅲ)和Ho(Ⅲ)等)形成九配位结构配合物,而Yb(Ⅲ)-EDTA则形成八配位结构配合物.     

现场拉曼光谱研究聚吡咯的去质子和氧化降解

利用电化学现场拉曼光谱结合循环伏安法，研究了中性和碱性溶液中聚吡咯（ＰＰＹ）膜的行为及其结构，结果表明，氧化ＰＰＹ中吡咯环Ｎ原子上的Ｈ失去发生去质子化，形成一种醌式结构，由于该酯式结构的出现使ＰＰＹ的Ｃ＝Ｃ伸缩振动峰发生分裂，且因该酯式结构不能被进一步氧化，以致ＰＨ值增大，去质子化程度提高，ＰＰＹ变得较难被氧化，而使其可逆性也受到一定程度的破坏，在ＰＨ－１３的强碱性溶液中，ＰＰＹ膜在正于０Ｖ的电位     

聚焦核心素养 展示生长课堂——以“多面体的外接球问题”的教学为例

多面体的外接球问题是高考数学中的热点问题,解决此类问题的关键是确定球心的位置.本文结合教学实践,着重介绍三种确定球心的方法(定义法、补形法、性质法),谈谈直观想象、数学抽象、数学运算等数学核心素养的培养.     

Observation of Three-Quasiparticle Doublet Bands in ^123I： Possible Evidence of Chirality

A new band in the odd proton nucleus ^123I is identified via in-beam γ-ray spectroscopy using the ^14N＋^116Cd reaction. This band shows up as doublets with the previously assigned π97/2 （vh11/2）^2 band. Possible configurations of the new band are discussed in the framework of the cranked shell model and the geometrical model It is argued that the new band might be a chiral partner of the previously known πg9/2 （vh11/2）2 band.     

锰(Ⅱ)-胡椒碱-溴化十六烷基三甲基胺三元体系的荧光特性及应用

The fluorescence characteristics of the complex of piperine with cation in micellar system were studied. At the same time, the influence of experimental condition on the fluorescence intensity was also studied. The experiments indicated that piperine had very low fluorescence signal itself. But in pH 8.77 Na₂HPO₄-NaH₂PO₄ buffer solution, both Mn(Ⅱ) and cationic surfactant cetyltrimethylammonium bromide can enhance the fluorescence intensity and stability of piperine. Based on this, a sensitive method has been developed for the quantitative determination of piperine in Mn(Ⅱ)-piperine-cetyltrimethylammonium bromide ternary system. Under the optimum conditions, there is a linear relationship between the enhancement of fluorescence intensity and the concentration of Mn(Ⅱ). The optimal conditions are as follows: the concentration of Mn(Ⅱ) is 2.5×10-4 mol·L-1 and the concentration of cetyltrimethylammonium bromide is 5×10-4 mol·L-1. The fluorescence intensity was determined by a 1 cm quartz cell with the excitation wavelength of 352 nm and the emission wavelength of 452 nm. The linear range of concentration of piperine was 2.02-10.1 μg·mL-1 with the relative coefficient of 0.998 5 and the detection limit of 0.060 2 μg·mL-1. The relative standard deviation (RSD) was 1.10%. The proposed method has been successfully applied to the quantitative determination of piperine in the Mongolian medicine Piper longum L, and the recovery was within the range of 97.6%-102.0%. The results were very satisfactory.     

双波长数字显微像面全息术测量微结构表面形貌EI北大核心CSCD

为了扩大传统双波长数字全息显微技术在实时微结构表面形貌测试中的有效测量视场,提高实时响应速度并降低噪声,将传统双波长数字全息术和数字显微像面全息术相结合,提出了一种双波长数字显微像面全息方法。该方法在记录像面全息图后,无需进行衍射重构,直接在全息面提取相位和强度信息达到测量样本形貌的目的。基于该方法对微米级高度的台阶结构进行三维形貌测试,同时对比了传统双波长数字全息显微系统和机械探针轮廓仪的微台阶测试结果。从三者的对比分析中可知,双波长数字显微像面全息的这种测试技术是有效可行的,且具有单曝光、全视场,响应速度快以及噪声较低的特点,对于阶跃高度达到微米级的微器件形貌测试尤为适用。     

胡椒酸丁二醇单脂与牛血清白蛋白相互作用的研究

运用荧光及紫外-可见吸收光谱法研究了胡椒酸丁二醇单酯(简称BPM)与牛血清白蛋白(BSA)的相互作用。实验结果表明,胡椒酸丁二醇单酯与BSA形成基态复合物导致BSA内源性荧光猝灭,猝灭机理主要为静态猝灭和非辐射能量转移,其猝灭速率常数为Kq为1.077×1013L/(mol.s)(25℃)、0.946×1013L/(mol.s)(37℃)。利用荧光猝灭反应测得结合常数KA为2.6×106(25℃)、3.4×106(37℃),结合位点数n为1.30(25℃)、1.33(37℃)。根据Frster能量转移理论得到结合距离r=2.92nm(25℃)、2.66nm(37℃)和能量转移效率E=0.45(25℃)、0.43(37℃)。通过热力学参数计算,确定胡椒酸丁二醇单酯与BSA的相互作用是熵增加和吉布斯自由能降低的自发过程,主要作用力是疏水作用力。     

Multi-physics analysis of the RFQ for Injector Scheme II of C-ADS driver linac

A 162.5 MHz, 2.1 MeV radio frequency quadruples （RFQ） structure is being designed for the Injector Scheme Ⅱ of the China Accelerator Driven Sub-critical System （C-ADS） linac. The RFQ will operate in continuous wave （CW） mode as required. For the CW normal conducting machine, the heat management will be one of the most important issues, since the temperature fluctuation may cause cavity deformation and lead to the resonant frequency shift. Therefore a detailed multi-physics analysis is necessary to ensure that the cavity can stably work at the required power level. The multi-physics analysis process includes RF electromagnetic analysis, thermal analysis, mechanical analysis, and this process will be iterated for several cycles until a satisfactory solution can be found. As one of the widely accepted measures, the cooling water system is used for frequency fine tunning, so the tunning capability of the cooling water system is also studied under different conditions. The results indicate that with the cooling water system, both the temperature rise and the frequency shift can be controlled at an acceptable level.