大气压光电离技术及其应用研究进展

大气压光电离离子源(APPI)是一种新兴的用于液质联用的软电离离子源,它是利用光化学作用将气相中样品电离的离子化技术,该技术促进了质谱技术对弱极性化合物的分析检测。介绍了液相色谱–质谱/质谱联用技术中大气压光电离的基本原理、应用优点,综述了其在定性、定量分析检测中的应用。     

Al2O3/ZrO2陶瓷激光近净成形工艺研究及性能分析

利用激光近净成形技术及未添加任何粘结剂的纯陶瓷粉末直接制备了Al2O3/ZrO2共晶陶瓷薄壁结构,对成形工艺进行了研究,获得了优化的工艺参数范围,并利用XRD、SEM及显微硬度测量等手段对成形样件的化学成分、微观组织、硬度及断裂韧性等进行了分析.结果表明,随激光功率的增加,成形件的裂纹呈先减少后增多的规律,裂纹数量在激光功率为454 W时开始明显减少,而当超过582 W时则又开始逐渐增多.成形样件的微观组织为共晶间距约100 nm的致密共品组织,主要由稳定的α-Al2O3与t-ZrO2构成,微观硬度最高可达17.5 GPa,断裂韧性为4.8 ±0.3 MPa·m1/2,达到了传统方法的制备水平.该研究表明激光近净成形技术基于陶瓷材料的熔化-凝固成形,为直接快速制备高性能陶瓷结构提供了一种全新的选择.     

学龄前儿童头发中九种元素分析

用原子吸收光谱法测定了长春市某幼儿园１２０名正常儿童头发中铁、锌、铜、锰、钙、镁、钠、钾、铅九种元素含量。对不同年龄、性别儿童发中各元素含量进行了对比分析,并对微量元素铁、锌、铜、锰含量与有关标准进行了比较,表明缺铁现象普遍存在,发铁缺乏率达９４．７４％以上。     

Z80仿真编程实验

本文介绍利用 Ｗｉｎｄｏｗｓ 操作系统下 Ｚ８０ 仿真软件,开设微机编程实验。     

银纳米粒子修饰的二维金属-有机框架纳米片用于光热增强银离子释放抗菌

近年来,二维(2D)金属-有机框架(MOF)纳米复合材料被广泛的应用于生物医学领域,尤其是在抗菌方面。在此,我们通过光照诱导还银离子成功在二维MOF纳米片上生长银纳米粒子,得到了一种银纳米粒子(Ag NPs)修饰的二维Zr-Fc-MOF (MOF-Ag)纳米片,并将其用于光热增强Ag⁺释放抗菌治疗。通过水热法和超声处理合成MOF纳米片,然后通过原位光辐照诱导还原在MOF纳米片上生长Ag NPs。系列表征结果表明Ag NPs成功负载到MOF纳米片上。聚乙烯吡咯烷酮(PVP)的修饰不仅可以增强MOF-Ag在溶液中的稳定性,还可以增强它的生物相容性。在近红外激光(NIR)照射下,MOF纳米片可以在短时间升温,而温度的升高可以加速Ag NPs在溶液中氧化为银离子。通过细菌生长曲线、菌落相对数和细菌形态变化等实验表明PVP@MOF-Ag纳米片具有优异的广谱杀菌性能。此外,2D MOF纳米片良好的光热性能不仅可以增强Ag⁺的释放,还可以增强细胞膜的通透性,随后进入细菌中的Ag⁺可以诱导内源性活性氧的产生,从而引发细菌的氧化应激,实现高效抗菌。基于良好的体外抗菌性能,进一步将PVP@MOF-Ag纳米片用于小鼠伤口愈合,在此期间PVP@MOF-Ag纳米片表现出良好的治疗效果和生物安全性。我们的研究结果表明,PVP@MOF-Ag纳米片可以作为光热增强Ag⁺释放抗菌治疗和伤口愈合的有效平台。     

Chaos game representation of functional protein sequences, and simulation and multifractal analysis of induced measures

Investigating the biological function of proteins is a key aspect of protein studies. Bioinformatic methods become important for studying the biological function of proteins. In this paper, we first give the chaos game representation (CGR) of randomly-linked functional protein sequences, then propose the use of the recurrent iterated function systems (RIFS) in fractal theory to simulate the measure based on their chaos game representations. This method helps to extract some features of functional protein sequences, and furthermore the biological functions of these proteins. Then multifractal analysis of the measures based on the CGRs of randomly-linked functional protein sequences are performed. We find that the CGRs have clear fractal patterns. The numerical results show that the RIFS can simulate the measure based on the CGR very well. The relative standard error and the estimated probability matrix in the RIFS do not depend on the order to link the functional protein sequences. The estimated probability matrices in the RIFS with different biological functions are evidently different. Hence the estimated probability matrices in the RIFS can be used to characterise the difference among linked functional protein sequences with different biological functions. From the values of the D_q curves, one sees that these functional protein sequences are not completely random. The D_q of all linked functional proteins studied are multifractal-like and sufficiently smooth for the C_q (analogous to specific heat) curves to be meaningful. Furthermore, the D_q curves of the measure \mu based on their CGRs for different orders to link the functional protein sequences are almost identical if q\geq 0. Finally, the C_q curves of all linked functional proteins resemble a classical phase transition at a critical point.     

系列线型［M_2M′S_4O_4］~（2－）簇的合成及光谱与结构的关系（M＝Mo，W；M′＝Co，Mi，Fe）

报道了６种线型簇合物［Ｅｔ_４Ｎ］_２［Ｍ_２Ｍ′Ｓ_４Ｏ_４］（Ｍ＝Ｍｏ，Ｗ；Ｍ′＝Ｃｏ，Ｎｉ，Ｆｅ）的合成，通过对ＵＶ－Ｖ_（ｉｓ）、ＩＲ及ＸＰＳ光谱的对比分析，讨论了簇阴离子［Ｍ_２Ｍ′Ｓ_４Ｏ_４］~２－中心金属Ｍ′的ｄ电子结构、氧化态以及［Ｍ′Ｓ_４］的微环境，由此推测了簇阴离子构型，并讨论了化合物的稳定性．     

系列线型[M2M‘S4O4]^2—簇的合成及光谱与结构的关系（M=Mo,W;M…

报道了６种线型簇合物（Ｅｔ４Ｎ）２（Ｍ２Ｍ＇Ｓ４Ｏ４）（Ｍ＝Ｍｏ，Ｗ；Ｍ＇＝ＣＯ，ＮＩ，Ｆｅ）的合成，通过对ＵＶ－Ｖｉｓ，ＩＲ及ＸＰＳ光谱的对比分析，讨论了簇阴离子（ＭＷＭ＇Ｓ４Ｏ４）＾２－中心金属Ｍ＇的ｄ电子结构、氧化态以及（Ｍ＇Ｓ４）的微环境，由此推了簇阴离子构型，并讨论了化合物的稳定性。     

张量力在16O+16O熔合动力学中的效应（英文）

利用时间相关Hartree-Fock 理论和完整Skyrme 有效相互作用研究了16O+16O 碰撞在库仑位垒附近的熔合动力学。数值计算是在没有任何对称性约束的三维笛卡尔基下完成。将时间相关Hartree-Fock 理论和冻结密度近似下的能量密度泛函方法给出的库仑位垒与实验结果进行了比较,发现同位旋标量的张量项能降低自旋饱和体系16O+16O的库仑位垒,而库仑位垒高度随着同位旋矢量的张量项的耦合常数减小而降低。并计算了包含和不包含张量力的16O+16O熔合截面,发现张量力对16O+16O碰撞在库仑位垒附近的熔合动力学影响较小。The fusion dynamics of 16O+16O around Coulomb barrier has been studied in the timedependent Hartree-Fock (TDHF) theory with the full Skyrme effective interaction. The calculations have been carried out in three-dimensional Cartesian basis without any symmetry restrictions. We have included the full tensor force and all the time-odd terms in Skyrme energy density functional (EDF). The Coulomb barrier obtained from the dynamical TDHF calculations and EDF with frozen density approximation has been compared with the available experimental data. The isoscalar tensor terms and the rearrangement of other terms are found to decrease the barrier height in the spin-saturated system 16O+16O, while the energy of Coulomb barrier tends to decrease as the isovector coupling constant decreases. The fusion cross section for 16O+16O collision has been calculated with and without the tensor force. We found that the tensor force has minor effect on the fusion dynamics of 16O+16O at the energies around Coulomb barrier.