Soft X-ray Holographic Microscopy with Sub-micrometer Resolution

Gabor X-ray in-line holograms are recorded with a photoresist at Hefei National Synchrotron Radiation Laboratory. An Atomic Force Microscope (AFM) is used to read the X-ray holograms of minute granules recorded on photoresist PMMA. Digitized hologram is reconstructed by numerical method. The granules with a size less than 0.3 μm can be resolved in the reconstructed image. So the eatimated resolution reaches the level of suibmicrometer.     

Simple and sensitive LC‐MS/MS‐based assay for the quantification of dimemorfan in human plasma for use in a pharmacokinetic study

Dimemorfan phosphate has been widely used for 40 years throughout the world for the treatment of coughs. This is the first report on the use of an LC‐MS/MS‐based assay for the determination of dimemorfan in human plasma using estazolam as an internal standard after one‐step protein precipitation with acetonitrile. Chromatographic separation was achieved on a Phenomenex Luna C₁₈ column (3 µm, 50 × 2.0 mm) using a fast gradient method, which involves water and methanol as the mobile phase (both containing 0.1% formic acid). Dimemorfan and estazolam were detected with proton adducts at m/z values of 255.8 → 155.1 and 295.0 → 267.0, respectively, in the selected reaction monitoring positive mode. The linear dynamic range of the assay was 0.04–5.00 ng/mL. The chromatographic run time for each plasma sample was <5 min. The method was proven to be accurate, precise, and repeatable. Finally, the developed method was successfully applied for the determination of dimemorfan in a pharmacokinetic study using healthy Chinese subjects. Copyright © 2014 John Wiley & Sons, Ltd.     

A concise design of 16 × 16 polymer AWG with low insertion loss and crosstalk

In this paper, a 16-channel arrayed waveguide grating multiplexer (AWG) has been designed using polymer materials with 1.5% refractive index difference. Certain important parameters are optimized using the coupling mode theory and Beam Propagation Method. The factors that affect the insertion loss and the crosstalk are analyzed in this paper. In our design we introduced the parabolic taper structure and evaluated the suitable number of the arrayed waveguide, obtaining a total insertion loss of 2.19 dB. For obtaining a low crosstalk we evaluate the pitches of adjacent input/output waveguides ΔX and arrayed waveguides d as different values. We chose the value of ΔX about 2.5 times of d by enlarging the pitches of adjacent input/output waveguides. The crosstalk of the designed AWG is lower than −40 dB.     

Y(PO3)3双包覆改性对Li[Ni0.8Co0.15Al0.05]O2电化学性能的影响

在镍钴铝酸锂正极材料 Li[Ni_0.8Co_0.15Al_0.05]O₂(NCA)制备过程中表面遗留的碱性物质会严重影响其循环稳定性能,针对这一难题,提出使用Y(PO₃)₃对其进行表面包覆改性,利用Y(PO₃)₃与表面残留的LiOH反应消除表面残碱,并探讨包覆改性对NCA整体性能的影响机制。测试分析结果表明,在低温煅烧过程中前驱体表面会形成均匀致密的Y(PO₃)₃和LiPO₃包覆层,LiPO₃有较高的离子电导率,双包覆层能够防止活性物质在电化学循环过程中与电解液相互接触时发生有害副反应,提高电极材料的循环稳定性。其中Y(PO₃)₃包覆量(质量分数)为1%的样品在0.1C下的首次库仑效率从未改性样品的78.65%提高到88.50%,在1C下循环150圈后容量保持率从59.38%提高到85.33%,相比于未改性样品具有更高的首次库仑效率和更优异的循环性能。     

Simultaneous measurement of temperature and strain using a long-period fiber grating with a micro-taper

An all-fiber Mach–Zehnder interferometer (MZI) consisting of a long-period fiber grating with a micro-taper is proposed for simultaneous measurement of temperature and strain. The experimental results demonstrate that the temperature and strain sensitivities of the proposed MZI are 83 pm/°C and ?2.6 pm/με, respectively. The strain sensitivity is 20 times as high as that of a long-period fiber written by CO₂ laser pulses combined with a fiber bitaper. In addition, the interferometer requires only a common single-mode fiber, and it is easy to fabricate and is inexpensive for temperature and strain sensing applications.     

分散固相萃取-液相色谱-串联质谱法测定谷物、蔬菜、水果中27种新型杀菌剂

建立了同时检测谷物、蔬菜和水果中27种新型杀菌剂的分散固相萃取-液相色谱-串联质谱(DSPE-LC-MS/MS)分析方法。样品经1%(体积分数)乙酸丙酮溶液提取,以无水硫酸镁(MgSO_4)脱水,经N-丙基乙二胺(PSA)、C_(18)、无水MgSO_4、多壁碳纳米管(MWCNT)混合净化剂净化,经C_(18)色谱柱分离,用乙腈和体积分数为0.1%的甲酸水溶液(含5 mmol/L乙酸铵)梯度洗脱,多反应监测(MRM)正离子模式扫描,采用外标法定量。噻呋酰胺和氯啶菌酯在20.47~200μg/kg范围内线性关系良好,其他25种新型杀菌剂在0.02~100μg/kg范围内线性关系良好,相关系数R~2≥0.995 0,加标回收率为70.02%~117.6%,相对标准偏差(RSD)为0.01%~19.62%(n=3)。噻呋酰胺和氯啶菌酯的检出限为6.15~16.67μg/kg,定量限为20.47~55.5μg/kg。其他25种新型杀菌剂的检出限为0.006~4.44μg/kg,定量限为0.02~14.79μg/kg。该方法简便、快速、可靠,可用于谷物、蔬菜、水果中27种新型杀菌剂的快速测定。     

Synthesis of Fe3O4-graphene-TiO2 ternary composite networks for enhanced capture of phosphopeptides

Fe(3)O(4)-graphene-TiO(2) ternary composite networks were first synthesized, which exhibited high selectivity and capacity in the capture of phosphopeptides, due to the enhanced contact to phosphopeptides given by the graphene scaffold.     

Research progress of triazole derivatives in the discovery of agricultural chemicals

Triazole groups play an important role in the construction of agricultural bioactive molecules, often acting as linking units to organically graft different pharmacophore groups, so as to obtain efficient and broad-spectrum pesticide molecules. After decades of development, triazole derivatives have made remarkable achievements in the discovery of pesticides, especially the discovery of fungicides. In addition, highly effective triazole insecticides, herbicides, and anti-plant virus agents have also been found, and commercial triazole pesticides have occupied a large market share. At present, the study of triazole compounds has become one of the important fields in the development of new pesticides. We systematically reviewed the application of triazole derivatives in the discovery of new pesticides since 2010, summarized the antifungal, antibacterial, insecticidal, herbicidal, and anti-plant virus activities of triazole derivatives, and discussed the structure–activity relationship and mechanism of action in order to provide inspiration and ideas for the discovery of new triazole agrochemicals.     

Passivity analysis for uncertain neural networks with discrete and distributed time-varying delays

In this Letter, the passivity problem of uncertain neural networks with discrete and distributed time-varying delays is investigated. New delay-dependent conditions for this problem are obtained by using a novel Lyapunov functional together with the linear matrix inequality (LMI) approach. Numerical examples are given to show the effectiveness of our theoretical results.     

利用强流ISOL束研究20Na的奇异衰变模式(英文)

北京放射性离子束装置（Beijing Radioactive Ion-beam Facility,BRIF）是基于在线同位素分离器技术的国家大科学平台。在BRIF装置上利用100 MeV的质子束轰击较厚的反应靶产生放射性核素;反应产物经离子源电离和在线分离,在线同位素分离段可引出100~300 keV的放射性核束,质量分辨率达20 000。在基金委科学仪器基础研究专项的支持下,建成了多用途的衰变实验终端,包括束流传输管道、通用靶室、带电粒子和γ探测器、集成电子学和数据获取系统等。利用100 MeV的质子束轰击MgO厚靶产生了流强高达1×105 pps的20Na放射性核束。通过高效率地同时测量β,γ和α,第一次直接观测到20Na非常稀有的β-γ-α衰变模式。Beijing Radioactive Ion-beam Facility(BRIF) has been commissioned as the national Radioactive Ion Beam(RIB) facility based on the Isotope Separator On Line(ISOL) technique since 2016. At BRIF, the radioactive nuclides are produced by the proton beam of 100 MeV bombarding a thick-target, the reaction products diffusing out of the target are ionized by an ion source and delivered to the online mass separator. In addition to the post-accelerated radioactive ion beams, BRIF can provide low-energy ISOL beams of 100 to 300 keV with a mass resolution of 20 000. A general-purpose decay station has been built including the ISOL beam transport line, a conventional reaction chamber, charge-particle and γ detectors with integrated electronics and data acquisition system. An intense 20Na ISOL beam up to 1×105 pps was produced by using the 100 MeV proton beam bombarding a MgO thick target. With high-efficiency measurements of β, γ and α simultaneously, very rare β-γ-α decay mode in 20Na has been directly observed for the first time in the present work.