多批次肝衰竭患者呼出气体的电喷雾萃取电离质谱检测及代谢组学数据分析

采用高分辨电喷雾萃取电离质谱(EESI-MS)技术对肝衰竭患者和健康志愿者呼出气体样本进行快速检测, 结合多块偏最小二乘分析(MB-PLS)方法, 对多批次获取的呼出气体代谢数据进行统计建模分析, 并与传统的PLS方法进行比较. 结果表明, MB-PLS方法能有效消除批次差异对统计建模的影响. 此外, 利用MB-PLS模型变量VIP值对变量进行筛选, 可降低数据的冗余, 消除无关变量对模型的影响, 从而有效提高了模型的性能.     

等效质量模型中的重子质量谱

在等效质量模型框架下,考虑线性禁闭和一阶微扰相互作用的贡献并通过拟合$ \mathrm{p} $、$ \mathrm{n}$、$\Lambda$和$ \Delta $的质量来得到模型参数。发现,等效质量模型能够较好地给出符合实验的重子质量谱。而禁闭强度$D$、强耦合常数$\alpha_{\rm{s}}$以及夸克质量因子$f$与微扰强度$C$之间都存在关联,并能够很好地用解析公式逼近。除此之外,单胶子交换相互作用的色磁部分在重子质量谱中起着重要作用,从而使自旋$J=1/2$和3/2的重子之间的质量差最高达到300 MeV。为了更好地描述超子质量,对于包含奇异夸克的一对夸克间的相互作用我们进一步采用不同的强耦合常数,其具体的模型参数通过拟合$ \Sigma $和$ \Xi $的质量得到。基于本工作得到的等效质量模型参数组,能够更好地描述$ \mathrm{ud}$夸克物质团、奇异子以及致密星。     

基于熔合蒸发反应的超重新元素 Z = 119, 120的产生截面

We have calculated production cross sections of new superheavy elements with atomic number Z=119, 120 in the fusion-evaporation reactions of $^{48}{\rm{Ca}}$+$^{252}{\rm{Es}}$, $^{48}{\rm{Ca}}$+$^{257}{\rm{Fm}}$, $^{49}{\rm{Sc}}$+$^{252}{\rm{Es}}$, $^{49}{\rm{Sc}}$+$^{251}{\rm{Cf}}$, $^{50}{\rm{Ti}}$+$^{247}{\rm{Bk}}$, $^{50}{\rm{Ti}}$+$^{251}{\rm{Cf}}$, $^{51}{\rm{V}}$+$^{247}{\rm{Cm}}$, $^{51}{\rm{V}}$+$^{247}{\rm{Cf}}$, $^{54}{\rm{Cr}}$+$^{243}{\rm{Am}}$, $^{54}{\rm{Cr}}$+$^{247}{\rm{Cm}}$, $^{56}{\rm{Mn}}$+$^{244}{\rm{Pu}}$, $^{56}{\rm{Mn}}$+$^{243}{\rm{Am}}$, $^{60}{\rm{Fe}}$+$^{237}{\rm{Np}}$, $^{60}{\rm{Fe}}$+$^{244}{\rm{Pu}}$, $^{61}{\rm{Co}}$+$^{238}{\rm{U}}$, $^{61}{\rm{Co}}$+$^{237}{\rm{Np}}$, $^{64}{\rm{Ni}}$+$^{231}{\rm{Pa}}$, $^{64}{\rm{Ni}}$+$^{238}{\rm{U}}$, $^{65}{\rm{Cu}}$+$^{232}{\rm{Th}}$, $^{65}{\rm{Cu}}$+$^{231}{\rm{Pa}}$, and $^{68}{\rm{Zn}}$+$^{232}{\rm{Th}}$within the dinuclear system model systematically. The inner fusion barriers have been extracted from the driving potential and potential energy surface which could be used to predict the relative fusion probability roughly. The influence of mass asymmetry of the colliding partners on the production of new superheavy elements(SHE) has been investigated systematically. It is found that fusion probability increases along with the increasing mass asymmetry of colliding systems. The 46-50Ti-induced reactions prefer to produce new SHE with Z=119~120. The dependence of production cross-sections of new superheavy elements on the isospin of projectile nuclei has been discussed. The new SHE of $^{289-293}{\rm{119}}$ has been predicted as the synthesis cross sections around one picobarn in the $^{44,\, 46,\, 48,\, 50}{\rm{Ti}}$-induced reactions. Production cross-section of the element$^{295}{\rm{120}}$ has been evaluated as large as one picobarn in the reactions $^{46}{\rm{Ti}}$($^{251}{\rm{Cf}}$, 2n) $^{295}{\rm{120}}$ at $E^*$ = 26 MeV. The optimal projectile-target combinations and beam energies for producing new SHE with atomic number Z = 119~120 are proposed for the forthcoming experiments.     

Comparative study of hollow-fiber liquid-phase micro-extraction and an aqueous two-phase system for determination of phytohormones in soil

Two methods, hollow-fiber liquid-phase micro-extraction (HF-LPME) and an aqueous two-phase system (ATPS), have been systematically optimized and compared for extraction and determination of phytohormones in soil by high-performance liquid chromatography (HPLC). The effects on extraction of conditions including solvent type and volume, extraction time, temperature, and amount of salt were evaluated. It was shown that ATPS was superior to HF-LPME for determination of paclobutrazol and uniconazole under the optimum conditions. The limits of detection (LODs) of ATPS were 0.002 μg g(-1) for uniconazole and 0.01 μg g(-1) for paclobutrazol, whereas LODs of HF-LPME were 0.005 μg g(-1) and 0.03 μg g(-1), respectively. Relative standard deviations (RSDs, n=5) and recovery were in the range 1.7-5.3 % and 86-102 %, respectively, for ATPS and 6.7-7.9 % and 40-60 % for HF-LPME. In addition, the advantages of ATPS were shorter extraction time, suitable for simultaneous pretreatment of batches of samples, and higher extraction capacity. ATPS was therefore applied to the determination of paclobutrazol and uniconazole in real soil samples. Uniconazole was detected in all the samples analyzed whereas paclobutrazol was not found.     

Surface-enhanced Raman scattering (SERS) optrodes for multiplexed on-chip sensing of nile blue A and oxazine 720

The fabrication and on-chip integration of surface-enhanced Raman scattering (SERS) optrodes are presented. In the optrode configuration, both the laser excitation and the back-scattered Raman signal are transmitted through the same optical fiber. The SERS-active component of the optrode was fabricated through the self-assembly of silver nanoparticles on the tip of optical fibers. The application of SERS optrodes to detect dyes in aqueous solution indicated a limit of quantification below 1 nM, using nile blue A as a molecular probe. Using the optrode-integrated microfluidic chip, it was possible to detect several different dyes from solutions sequentially injected into the same channel. This approach for sequential detection of different analytes is applicable to monitoring on-chip chemical processes. The narrow bandwidth of the vibrational information generated by SERS allowed solutions of different compositions of two chemically similar dyes to be distinguished using a dilution microfluidic chip. These results demonstrate the advantages of the SERS-optrode for microfluidics applications by illustrating the potential of this vibrational method to quantify components in a mixture.     

联1,2-二氢咪唑并苯并咪唑的水相绿色合成

1,2-二氢咪唑并苯并咪唑衍生物具有杀菌等生物活性。为了进一步研究其抗真菌活性,于室温下以2-氨甲基苯并咪唑与乙二醛在水中反应,高产率水相绿色合成了联1,2-二氢咪唑并苯并咪唑,产率达88.6%,进一步讨论了反应的机理。     

利用Diels-Alder反应构建桉烷类倍半萜骨架关键中间体的研究

以3-甲基-1,3-间苯二酚和异戊醛为原料分别合成亲双烯2-甲氧基-6-甲基对苯醌和双烯1-甲氧基-3-异丙基-1,3-丁二烯,通过Diels-Alder反应,高区域选择性地得到桉烷类倍半萜骨架中间体2c.     

加脊TEM喇叭初步研究

针对恒阻抗TEM喇叭的上下面板电流分布不对称,采用小反射理论和阻抗渐变思想并通过设计脊结构对恒阻抗TEM喇叭进行了改进,研制了加脊TEM喇叭。仿真及实验研究结果表明:对于脉冲宽度约为1 ns的高斯脉冲,通过加脊在一定程度上改善了恒阻抗TEM喇叭上下面板电流分布的不对称性和E面辐射电场的不对称性;相对于相同口径的恒阻抗TEM喇叭,加脊TEM喇叭作为辐射天线和反射面脉冲天线馈源时系统的主轴远场辐射因子均有提高。     

Hill-Type Formula and Krein-Type Trace Formula for Hamiltonian Systems

In this paper, we give a survey on the Hill-type formula and its applications.Moreover, we generalize the Hill-type formula for linear Hamiltonian systems and Sturm-Liouville systems with any self-adjoint boundary conditions, which include the standard Neumann, Dirichlet and periodic boundary conditions. The Hill-type formula connects the infinite determinant of the Hessian of the action functional with the determinant of matrices which depend on the monodromy matrix and boundary conditions. Further, based on the Hill-type formula, we derive the Krein-type trace formula. As applications, we give nontrivial estimations for the eigenvalue problem and the relative Morse index.     

Fabrication of niobium doped titanate nanoflakes with enhanced visible-light-driven photocatalytic activity for efficient ibuprofen degradation

In this study, a novel class of niobium (Nb) doped titanate nanoflakes (TNFs) are fabricated through a one-step hydrothermal method. Nb doping affects the curving of titanate nanosheet, leading to the formation of nanoflake structure. In addition, Nb⁵⁺ filled in the interlayers of [TiO₆] alters the light adsorption property of pristine titanate. The band gap of Nb-TNFs is narrowed to 2.85 eV, while neat titanate nanotubes (TNTs) is 3.4 eV. The enhanced visible light adsorption significantly enhances the visible-light-driven activity of Nb-TNFs for ibuprofen (IBP) degradation. The pseudo-first order kinetics constant for Nb-TNFs is calculated to be 1.04 h^?1, while no obvious removal is observed for TNTs. Photo-generated holes (h⁺) and hydroxyl radicals (OH) are responsible for IBP degradation. The photocatalytic activity of Nb-TNFs depends on pH condition, and the optimal pH value is found to be 5. In addition, Nb-TNFs exhibited superior photo-stability during the reuse cycles. The results demonstrated Nb-TNFs are very promising in photocatalytic water purification.