Real-time phase measurement and correction of dynamic multimode beam using a single spatial light modulator

In this Letter,a novel system for adaptively correcting the phase of a dynamic multimode beam is proposed.While using merely one spatial light modulator,the phase measurement of the first-order diffraction pattern and the correction of the zeroth diffraction order are simultaneously realized.The real-time experimental result is obtained at a control rate of 10 Hz.The power-in-the-bucket value is improved from 38.5%to 61.8%,even with fundamental mode content that is consistently below 30%.To the best of our knowledge,this is the first implementation of real-time adaptive correction of the entire multimode beam.     

Identifying anomalous Floquet edge modes via bulk-edge correspondence

Floquet engineering appears as a new protocol for designing topological states of matter,and features anomalous edge modes pinned at quasi-energy π/T with vanished topological index.We propose how to predict the anomalous edge modes via the bulk Hamiltonian in frequency space,and use Zak phase to quantitatively index the topological properties.The above methods are clarified by the example of time periodic Kitaev chain with chemical potential of harmonic driving and pulse driving,and topological phase transitions are manifested at different driving frequencies.     

Green synthesis,characterization and physiological stability of gold nanoparticles from Stachys lavandulifolia Vahl extract

The synthesis of nontoxic stable gold nanoparticles is important for medical applications.An aqueous extract of the plant Stachys lavandulifolia Vahl was used to synthesize gold nanoparticles.This green method involved the S.lavandulifolia Vahl extract acting as a reducing and stabilizing agent.The nanoparticles were characterized by transmission electron microscopy,dynamic light scattering analysis and UV-vis absorption and Fourier transform-infrared spectroscopies.Stability under physiological conditions is important for medical applications.The stability of the nanoparticles was compared with that of conventional citrate-capped nanoparticles,under both synthetic and physiological conditions.The nanoparticles synthesized from the S.lavandulifolia Vahl extract were stable under physiological conditions,in contrast with conventional citrate-capped nanoparticles.     

Evaluation of the performance of a soft X-ray charger for the bipolar charging of nanoparticles

The use of soft X-rays in a neutrahzer represents an alternative technique that could replace conventional radioactive sources.In this study,we evaluated the charging characteristics of a soft X-ray aerosol neutralize!".In addition,the results from the evaluation of the soft X-ray charger were compared with results obtained using a neutralizer incorporating an ²⁴¹Am radioactive source.The tandem differential mobility analyzer technique was used previously to determine the size-dependent positive,negative,and neutral charge fractions of a soft X-ray neutralizer.This technique was used to show that the neutral fractions obtained using the soft X-ray charger agreed well with the predictions of bipolar diffusion charging theory,and that the soft X-ray charger could be used as a neutralizer for a scanning mobility particle sizer system.     

An effective interference suppression algorithm for visible light communication system based on DBSCAN

In order to improve the signal-to-noise ratio and mitigate the damage of noise to the communication quality,an effective interference suppression algorithm,which is based on the improved density-based spatial clustering of applications with noise algorithms,is proposed for visible light communication systems using the complementary metal–oxide–semiconductor image sensor as the receiver.Experimental results show that the algorithm can learn the region where the payload data is located,filter out the noise data,and greatly decrease the interference.The effect of the algorithm is also studied through bit error ratio performance.     

新型嘧啶-水杨酸类抑制剂的设计、合成及其生物活性研究

乙酰羟酸合成酶(Acetohydroxyacid synthase, AHAS)是一类重要的除草剂靶标,但是靶向AHAS的抑制剂是所有除草剂类型中抗性最为严重的一类,因此设计具有反抗性的AHAS抑制剂显得尤为必要.本工作基于前期低抗性AHAS抑制剂结构,利用"构象柔性度分析"的设计策略合理增加分子柔性,设计并合成了13个含"双氧桥"结构的嘧啶水杨酸类抑制剂.目标分子均经过氢谱(~1H NMR)、碳谱(~(13)C NMR)和高分辨质谱(HRMS)确证.酶水平活性结果显示,部分化合物对P197L突变体表现出了微摩尔水平的抑制作用,特别是2-((4,6-二甲氧基嘧啶-2-基)氧基)-6-(2-氟-4-硝基苯氧基)-4-甲基苯甲酸(6l)对P197L突变体表现出了良好的反抗性.盆栽除草活性结果表明,个别化合物对抗性杂草播娘蒿具有一定的除草活性,其中2-((4,6-二甲氧基嘧啶-2-基)氧基)-6-(2-氟苯氧基)-4-甲基苯甲酸(6b)在150g ai/ha浓度下,对敏感生物型播娘蒿和抗性播娘蒿均达到80%的除草防效,具有进一步深入研究的价值.     

One-dimensional Intrinsic Ferromagnetic Semiconductor CuCl_2: a First-principles Study

One-dimensional nanowires with robust magnetism are desirable for spintronic applications. Herein, on the basis of the first-principles calculations, systematic investigations on the electronic and magnetic properties of the CuCl2 nanowire were performed, which can be potentially tailored from its bulk form. The CuCl2 nanowire exhibits a ferromagnetic ground state. The band structures indicate that the CuCl2 nanowire is a ferromagnetic semiconductor. The spin flip gap is large enough for avoiding spin flip. Phonon dispersion and Born-Oppenheimer molecular dynamics simulation manifest that the CuCl2 nanowire is stable. In addition, distinct magnetic properties of the CuCl2 nanowires inside two types of carbon nanotubes were obtained. The study broadens the family of the existing one-dimensional materials with promising applications for spintronics.     

岩石可能保存有暗物质化石

<正>我们脚下的岩石中可能含有过去暗物质相互作用的残留物,这些残留物以纳米粗的径迹的形式存在着。以前对这些所谓的暗物质化石的寻找没有任何结果。但是瑞典和波兰的研究团队认为,最近在材料分析技术方面的进展,会促进新一     

水下多级微结构液气界面的稳定性和可恢复性研究

微结构表面浸没水下所形成的液气界面对减阻等应用具有重要意义.液气界面的稳定存在是结构功能表面发挥作用的前提.因此,如何增强液气界面的稳定性以抵抗浸润转变过程,以及在液气界面失稳之后,如何实现去浸润过程以提高液气界面的可恢复性能,均具有重要的科学研究意义和实际应用价值,也是国内外研究关注的热点问题.本文针对具有多级微结构的固体表面,研究其在浸没水下后形成的液气界面的稳定性和可恢复性.通过激光扫描共聚焦显微镜对不同压强下液气界面的失稳过程和降压后的恢复过程进行原位观察,实验结果和基于最小自由能原理的理论分析相吻合.本文揭示了多级微结构抵抗浸润转变以及提高液气界面可恢复性能的机理:侧壁上的次级结构(纳米颗粒、多层翅片)通过增加液气界面在壁面的表观前进接触角增强了液气界面的稳定性;底面的次级结构(纳米颗粒和封闭式次级结构)可以维持纳米尺寸气核的存在,有利于水中溶解气体向微结构内扩散,最终使液气界面恢复.本文的研究为通过设计多级微结构表面来获得具有较强稳定性和可恢复性的液气界面提供了思路.