Electrospinning-Enabled Si/C Nanofibers with Dual Modification as Anode Materials for High-Performance Lithium-Ion Batteries

In this work,silicon@reduced graphene oxide/pyrolytic carbon nanofibers(Si@RGO/C NFs) composite with double modified layer is prepared through electrospinning,stabilization and carbonization.In this composite,polyethylene oxide-polypropylene oxide-polyethylene oxide(P123,a non-ionic surfactant) is introduced as the dispersant,which can make silicon nanoparticles evenly dispersed in electrospinning solution to prevent it from agglomeration.Graphene modified layer can buffer the volumetric expansion of silicon nanoparticles,prevent direct contact between silicon and electrolyte as well as enhance the electrical conductivity.Moreover,carbon fibers synthesized by electrospinning can encapsulate silicon@graphene composite internally to form a double modified layer.This composite with double modified layer can further alleviate the volume change of silicon nanoparticles and avoid direct contact between silicon and electrolyte to form a stable interface.Owing to the above-mentioned merits,the Si@RGO/C NFs composite exhibits excellent cyclic stability and superior rate performance.Particularly,it maintains a specific capacity of 929 mA h g~(-1) with the retention ratio of 83.1% after 100 cycles at 0.5 A g~(-1) and delivers an outstanding rate capability of 1003 mA h g~(-1) at 2 A g~(-1).     

基于混合门单元的非平稳时间序列预测

非平稳多变量时间序列(non-stationary multivariate time series, NSMTS)预测目前仍是一个具有挑战性的任务.基于循环神经网络的深度学习模型,尤其是基于长短期记忆(long short-term memory, LSTM)和门循环单元(gated recurrent unit, GRU)的神经网络已获得了令人印象深刻的预测性能.尽管LSTM结构上较为复杂,却并不总是在性能上占优.最近提出的最小门单元(minimal gated unit, MGU)神经网络具有更简单的结构,并在图像处理和一些序列处理问题中能够提升训练效率.更为关键的是,实验中我们发现该门单元可以高效运用于NSMTS的预测,并达到了与基于LSTM和GRU的神经网络相当的预测性能.然而,基于这3类门单元的神经网络中,没有任何一类总能保证性能上的优势.为此提出了一种线性混合门单元(MIX gated unit, MIXGU),试图利用该单元动态调整GRU和MGU的混合权重,以便在训练期间为网络中的每个MIXGU获得更优的混合结构.实验结果表明,与基于单一门单元的神经网络相比,混合2类门单元的MIXGU神经网络具有更优的预测性能.     

基于响应面法优化双酶耦合超高压提取香菇多糖工艺及抗氧化活性研究

目的：香菇多糖（Lentinan,LNT）已被证明对癌细胞具有直接的细胞毒性。然而,这种抗肿瘤作用机制尚不清楚。本研究旨在探讨香菇多糖对胰腺癌细胞增殖、迁移及化疗敏感性的影响及其机制。方法：将胰腺癌Capan-1细胞随机分为对照组、IL-6组、IL-6+LNT组,MTT检测细胞存活率,Western blot检测p-STAT3、STAT3、Notch1和Hes1表达水平,Transwell实验检测细胞迁移。建立顺铂耐药细胞模型（Capan-1/DDP）,检测各组顺铂半抑制浓度（IC₅₀）,分析Ki-67、MMP-9、MRP1和P-gp蛋白相对表达水平。选择Capan-1/DDP细胞株进行裸鼠成瘤实验,验证LNT对裸鼠体内瘤体的瘤重、IL-6/STAT3/Notch信号通路的影响。结果：7.5~240 µg/mL香菇多糖对胰腺癌细胞增殖有抑制作用;与IL-6组比较,IL-6+LNT组增殖率显著降低,p-STAT3/STAT3、Notch1和Hes1表达和迁移水平（极）显著下调（P<0.05,P<0.01）;与IL-6组比较,IL-6+LNT组Capan-1/DDP细胞株增殖率极显著下调,IC₅₀极显著降低,Ki-67、MMP-9、MRP1和P-gp表达水平显著下调（P<0.05,P<0.01）。体内实验显示,与IL-6组比较,顺铂+IL-6组、LNT+IL-6组瘤体体积、瘤重极显著下调,p-STAT3/STAT3、Notch1、Hes1表达水平（极）显著降低（P<0.05,P<0.01）。结论：LNT抑制胰腺癌Capan-1细胞增殖、迁移和耐药,与调控IL-6/STAT3/Notch信号通路相关。

     

彩电遥控发射电路的研制与生产

本文介绍采用先进的ｎ阶硅栅ＣＭＯＳ枝术，研制出的遥控发射电路．其性能符合设计和用户提出的要求，达到了国外同类产品的指标，可以在彩电遥控发射器上直接互换使用．     

Improving rate capability and decelerating voltage decay of Li-rich layered oxide cathodes by chromium doping

In order to improve the rate capability and mitigate the voltage decay of lithium rich layered oxides, chromium doped cathode materials Li_1.2[Mn_0.54Ni_0.13Co_0.13]_1?xCr_xO₂ (x = 0,0.003,0.005,0.007) is synthesized via co-precipitation method followed by calcination. As a result, Cr-doped samples present shortened voltage platform at 4.5 V, indicating that the escape of lattice oxygen is suppressed by Cr doping. Among all samples, Li_1.2[Mn_0.54Ni_0.13Co_0.13]_1?xCr_xO₂ (x = 0.005) sample shows the greatest rate capability (119.3 mAh g^?1 at 10 C) and the minimum voltage drop (0.6167 V) after 200 cycles at 1.0 C. The reasons for the improved electrochemical performance are the enhanced structural stability, the stronger CrO bond than MnO band and the decreased metal–oxygen covalency induced by Cr doping.     

Advances in the Genetically Engineered KillerRed for Photodynamic Therapy Applications

Photodynamic therapy (PDT) is a clinical treatment for cancer or non-neoplastic diseases, and the photosensitizers (PSs) are crucial for PDT efficiency. The commonly used chemical PSs, generally produce ROS through the type II reaction that highly relies on the local oxygen concentration. However, the hypoxic tumor microenvironment and unavoidable dark toxicity of PSs greatly restrain the wide application of PDT. The genetically encoded PSs, unlike chemical PSs, can be modified using genetic engineering techniques and targeted to unique cellular compartments, even within a single cell. KillerRed, as a dimeric red fluorescent protein, can be activated by visible light or upconversion luminescence to execute the Type I reaction of PDT, which does not need too much oxygen and surely attract the researchers’ focus. In particular, nanotechnology provides new opportunities for various modifications of KillerRed and versatile delivery strategies. This review more comprehensively outlines the applications of KillerRed, highlighting the fascinating features of KillerRed genes and proteins in the photodynamic systems. Furthermore, the advantages and defects of KillerRed are also discussed, either alone or in combination with other therapies. These overviews may facilitate understanding KillerRed progress in PDT and suggest some emerging potentials to circumvent challenges to improve the efficiency and accuracy of PDT.     

放射性核素碘的纸上电泳及纸上层析研究

纸上电泳用于判别溶液中离子存在形式,研究价态分布情况及电荷极性等。该方法设备简单,操作方便,速度快、取样量少,且结果直观,判断正确,适用于半衰期短的放射性样品分析,是电化学研究的一个有效的方法。 用纸上电泳进行放射性碘的不同氧化态的分离工作,国外也早已开展。他们采用各种中性及硷性溶液作电解液,研究了I-、IO_3~-、1O_4~-的电泳图。Shukla等报道了在NaOH及NaCl介质中~(131)I~-、~(131)IO_3~-、~(131)IO_4~-的纸上电泳分离及碲存在下碘的不同氧化态的分布。Dreyer等则分别用KCI、NaH_2PO_4、NaNO_3作电解液,     

上软下硬地层浅埋暗挖工法适应性模拟

以青岛地区埋置于上软下硬典型地层中的地铁车站为例,选取双侧壁导坑法和单拱大空间法,利用三维有限元软件对两种施工方法的整个开挖过程进行数值模拟,重点对开挖过程中的地表和拱顶位移、围岩应力和支护结构内力等方面进行了分析.研究表明,与单拱大空间施工方法相比较,在上软下硬地层中采用双侧壁导坑施工方法能有效控制地表和拱顶沉降以及...     

甘蔗黄原酸酯处理六价铬的研究

对甘蔗黄原酸酯(SCX)的合成进行了研究,结果表明最佳合成条件为:蔗渣3g,用浓度为20%的NaOH溶液100mL,先电动搅拌1h,再交联24h,在碱性条件下,于制得的蔗渣碱性纤维素中逐滴加入0.4mLCS2/(g纤维素)进行黄化反应2h,采用浓度5%硫酸镁100mL进行转型反应,所得SCX产品去除金属离子的性能最佳,用于处理含100mg/L的六价铬离子废水,去除率高达99%。反应后的碱废液可以重复利用。     

Fracture‐Based Fabrication of Normally Closed,Adjustable, and Fully Reversible Microscale Fluidic Channels

Adjustable fluidic structures play an important role in microfluidic systems. Fracture of multilayered materials under applied tension has been previously demonstrated as a convenient, simple, and inexpensive approach to fabricate nanoscale adjustable structures; here, it is demonstrated how to extend this concept to the microscale. This is achieved by a novel pairing of materials that leverages fracture mechanics to limit crack formation to a specified region, allowing to create size‐controllable and adjustable microfluidic structures. This technique can be used to fabricate “normally closed” microfluidic channels that are completely reversible, a feature that is challenging to achieve in conventional systems without careful engineering controls. The adjustable microfluidic channels are then applied to mechanically lyse single cells, and subsequently manipulate the released nuclear chromatin, creating new possibilities for epigenetic analysis of single cells. This simple, versatile, and robust technology provides an easily accessible pathway to construct adjustable microfluidic structures, which will be useful in developing complex assays and experiments even in resource‐limited settings.