以“偏光显微镜观察高聚物的球晶”为例的高分子物理实验项目改革

本文对高分子物理实验教学改革进行了思考,提出实验项目的建设应当成为实验教学改革的核心,而实验项目的改革不应当局限在将最新的科研成果引入到实验教学中。以"偏光显微镜观察聚合物的球晶"这一传统实验为例,更为有效的办法可以是通过系统化的设计扩展实验项目内容,注重实验项目实施过程中多知识点的串联以及实验结果获取过程的思维过程培养,从而将传统的验证性实验项目转化为综合性实验项目,有力提升实验教学的效果。     

Some results on exclusive sum graphs

Let N(Z) denote the set of all positive integers (integers). The sum graph G ⁺(S) of a finite subset S?N(Z) is the graph (S,E) with uv∈E if and only if u+v∈S. A graph G is said to be an (integral) sum graph if it is isomorphic to the sum graph of some S?N(Z). A sum labelling S is called an exclusive sum labelling if u+v∈S?V(G) for any edge uv∈E(G). We say that G is labeled exclusively. The least number r of isolated vertices such that G∪rK ₁ is an exclusive sum graph is called the exclusive sum number ε(G) of graph G. In this paper, we discuss the exclusive sum number of disjoint union of two graphs and the exclusive sum number of some graph classes.     

Establishment and validation of an SIL-IS LC–MS/MS method for the determination of ibuprofen in human plasma and its pharmacokinetic study

In this work, we developed and validated a highly sensitive, rapid and stable LC–MS/MS method for the determination of ibuprofen in human plasma with ibuprofen-d3 as a stable isotopically labeled internal standard (SIL-IS). Human plasma samples were prepared by one-step protein precipitation. The chromatographic separation was achieved on a Poroshell 120 EC-C₁₈ (2.1 × 50 mm, 2.7 μm). Aqueous solution (containing 0.05% acetic acid and 5 mm NH₄Ac) and methanol were selected as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in negative ion mode. Multiple reaction monitoring mode was used for quantification using target fragment ions m/z 205.0 → 161.1 for ibuprofen and m/z 208.0 → 164.0 for SIL-IS, respectively. This method exhibited a linear range of 0.05–36 μg/ml for ibuprofen with correlation coefficient >0.99. Mean recoveries of ibuprofen in human plasma ranged from 78.4 to 80.9%. The RSD of intra- and inter-day precision were both < 5%. The accuracy was between 88.2 and 103.67%. The matrix effect was negligible in human plasma, including lipidemia and hemolytic plasma. A simple, efficient and accurate LC–MS/MS method was successfully established and applied to a pharmacokinetic study in healthy Chinese volunteers after a single oral administration of ibuprofen granules.     

HPLC/MS测定蒲公英颗粒中绿原酸、咖啡酸和阿魏酸的含量

建立了同时测定蒲公英颗粒中绿原酸、咖啡酸和阿魏酸3种酚酸物质含量的HPLC-MS方法.样品用含5%甲酸的甲醇溶液超声提取后,在Zorbax Eclipse XDB-C18(2.1mm×150mm,5μm)色谱柱上,以含0.2%甲酸的水(A)-乙腈(B)体系为流动相,进行梯度洗脱,线性梯度洗脱程序为:Omin,5%B;1.5min,10%B;10min,40%B;流速:0.25mL/min;在ESI正离子模式下,采用选择性离子监测方法进行检测.结果显示,绿原酸、咖啡酸和阿魏酸的线性范围分别为0.050～20.0、0.030～20.0和0.100～20.0μg/mL,检出限分别为0.010、0.006和0.020μg/mL.平均加标回收率为96.4%～101.6%,相对标准偏差为1.7%～3.3%.样品在10 h内测定基本不变,可用于蒲公英颗粒的质量控制.     

Fe3+‐Montmorillonite: An Efficient Solid Catalyst for One‐Pot Synthesis of Decahydroacridine Derivatives

Fe³⁺‐montmorillonite was used as a solid acidic catalyst for the synthesis of decahydroacridine derivatives through the condensation of aromatic aldehydes, dimedone and aniline in ethanol. The influence of reaction time, reaction temperature, and the amount of catalyst were studied. All the compounds were characterized by IR, Mp, ¹H NMR and ¹³C NMR analysis.     

Electrochemical sensor for rutin detection based on Au nanoparticle-loaded helical carbon nanotubes

The key step in the fabrication of highly active electrochemical sensors is seeking multifunctional nanocomposites as electrode modified materials. In this study, the gold nanoparticle-decorated helical carbon nanotube nanocomposites (AuNPs-HCNTs) were fabricated for rutin detection because of its superior sensitivity, the chemical stability of AuNPs, and the superior conductivity and unique 3D–helical structure of helical carbon nanotubes. Results showed the prepared nanocomposites exhibited superior electrocatalytic activity towards rutin due to the synergetic effects of AuNPs and HCNTs. Under the optimized conditions, the developed sensor exhibited a linear response range from 0.1 to 31 μmol/L for rutin with a low detectable limit of 81 nmol/L. The proposed method might offer a possibility for electrochemical analysis of rutin in Chinese medical analysis or serum monitoring owing to its low cost, simplicity, high sensitivity, good stability, and few interferences against common coexisting ions in real samples.     

高效液相色谱-质谱法同时测定清热解毒口服液中的5种有效成分

建立了同时测定清热解毒口服液中的绿原酸、栀子苷、黄芩苷、连翘苷和靛玉红5种有效成分的高效液相色谱-电喷雾电离质谱（HPLC-ESI/MS）分析方法。采用Zorbax SB C18色谱柱,以含0.2%甲酸的0.4 mmol/L醋酸钠(A相)、乙腈(B相)为流动相进行梯度洗脱,在ESI正离子模式下,采用选择离子监测方法进行测定,用峰面积进行定量。结果表明,绿原酸、栀子苷、黄芩苷、连翘苷和靛玉红的线性范围分别为0.050～50 mg/L,0.020～20 mg/L,0.005～30 mg/L,0.010～15 mg/L和0.010～10 mg/L;检出限分别为0.010,0.005,0.001,0.002和0.003 mg/L。5种成分的加样回收率为97.0%～101.7%,相对标准偏差小于2.2%。该法快捷、准确、重复性好,可用于清热解毒口服液中的5种有效成分含量的同时测定。     

Strong cosmic censorship for a scalar field in an Einstein-Maxwell-Gauss-Bonnet-de Sitter black hole

It has been shown that the Christodoulou version of the strong cosmic censorship(SCC)conjecture can be violated for a scalar field in a near-extremal Reissner-Nordstrom-de Sitter black hole.In this paper,we investigate the effects of higher derivative corrections to the Einstein-Hilbert action on the validity of SCC,by considering a neutral massless scalar perturbation in 5 -and 6 -dimensional Einstein-Maxwell-Gauss-Bonnet-de Sitter black holes.Our numerical results show that the higher derivative term plays a different role in the d=5 case than it does in the d=6 case.For d=5 ,the SCC violation region increases as the strength of the higher derivative term increases.For d=6 ,the SCC violation region first increases and then decreases as the higher derivative correction becomes stronger,and SCC can always be restored for a black hole with a fixed charge ratio when the higher derivative correction is strong enough.Finally,we find that the C² version of SCC is respected in the d=6 case,but can be violated in some near-extremal regimes in the d=5 case.     

N-取代-5-磺酰基吡唑肟醚衍生物的合成及生物活性研究

以吡唑酮、盐酸羟胺、硫酚、2-氯-5-氯甲基吡啶等化合物为原料,设计合成了5个未见文献报道的磺酰基吡唑肟醚新化合物,其结构经元素分析、1HNMR、IR和MS验证。初步生物活性测试表明,部分化合物具有一定的杀菌活性。     

Hidden conformal symmetry of rotating charged black holes

Motivated by the recent work of the hidden conformal symmetry of the Kerr black hole, we investigate the hidden conformal symmetry of a Kerr–Sen black hole and a Kerr–Newman–Kasuya black hole. Our result shows the conformal symmetry is spontaneously broken due to the periodicity of the azimuthal angle. The absorption across section is in consistence with the finite temperature absorption cross section for a 2D CFT. The entropies of the black holes are reproduced by the Cardy formula.