One‐Step Synthesis of Natural Silk Sericin‐Based Microcapsules with Bionic Structures

Different techniques are being developed for fabricating microcapsules; it is still a challenge to fabricate them in an efficient and environment‐friendly process. Here, a one‐step green route to synthesize silk protein sericin‐based microcapsules without any assistance of organic solvents is reported. By carefully changing the concentration of calcium ions accompanied with stirring, the morphology of the microcapsules can easily be regulated to form either discoidal, biconcave, cocoon‐like, or tubular structures. The chelation of Ca²⁺ and shearing force from agitation may induce the conformational transformation of sericin, which possibly results in the formation of microcapsules through the self‐assembly of the protein subsequently. The as‐prepared cocoon‐like microcapsules exhibit pH‐dependent stability. A potential application of microcapsules being fabricated from natural water‐soluble silk protein sericin for controlled bioactive molecules loading and release system by a pH‐triggered manner is quite feasible.

     

Femtosecond laser induced photoluminescence in poly(methyl methacrylate) and three-dimensional optical storage

We report on a femtosecond-laser induced photoluminescence (PL) in poly(methyl methacrylate) and its potential application to three-dimensional optical storage. Irradiation with a focused 800 nm, 1 kHz, 100 fs pulsed laser induced a strong PL change in UV-visible region. Absorption spectra and Fourier-transform infrared spectra before and after laser irradiation indicate the PL may result from the emissive oxidized products of photo-degradation reaction of PMMA. This makes it possible to read out the stored data by detecting the PL change. The pulse energy threshold of the light-induced PL change of PMMA is found to be at ∼2 μJ/pulse and the optimal recording energy is ∼3 μJ/pulse. A ten-layer pattern inside the bulk sample recorded by tightly focusing a pulsed laser beam was read out by a reflection-type fluorescent confocal microscope, which detected the emission in visible range as the signal. High-contract fluorescent images with a much higher signal-to-noise ratio were obtained without crosstalk in comparison with the ordinary reflection mode.     

Deformable double-shelled hollow mesoporous organosilica nanocapsules:A multi-interfacial etching strategy

Multishelled hollow structures have drawn increasing interest because of their peculiar compartmentation environments and physicochemical properties.In this work,deformable double-shelled hollow mesoporous o rganosilica nanocapsules(DDHMONs) were succes s fully synthesized by a multi-interfacial etching strategy.The obtained DDHMONs have a double-shelled structure with aninorganic-organic hybrid framework,a uniform outer layer(～320 nm) and inner layer(～180 nm),ordered mesochannels(～2.21 nm),and a large specific surface area(～1233 m~2/g).In vitro toxicity tests show that the DDHMONs have excellent biocompatibility when coincubated with human breast cancer cells.In addition,the anti cancer substance doxorubicin(DOX) can be highly loaded in DDHMONs(～335 μg/mg).The results from flow cytometry together with confocal laser scanning microscopy show that DOX can be efficiently delivered into MCF-7 cells by DDHMONs,thus improving chemotherapeutic efficiency and demonstrating that DDHMONs have potential nanomedicine applications as anticancer agents.     

包头混合稀土精矿络合浸出的研究

根据Al3+或Fe3+与F-能形成稳定的络合离子[AlF6]3-或[FeF6]3-,分别用HCl-AlCl3和HCl-FeCl3溶液络合浸出包头混合稀土精矿中的氟碳铈矿,并对两者进行了对比.结果表明,用HCl-AlCl3体系的精矿浸出率和稀土浸出率比用HCl-FeCl3体系的都高30％;在HCl浓度4.0 mol·L-1,Al3+浓度2.0 mol ·L-1,温度85℃,浸出时间120 min,液固比为30:1的条件下,稀土精矿中氟碳铈矿的浸出率达到了97.69％,氟碳铈矿中稀土浸出率达到了92.23％,进而使稀土精矿中的氟碳铈矿基本完全进入溶液中,达到与独居石分离的目的.     

Dynamic and stability analysis of a cantilever beam system excited by a non-ideal induction motor

Meccanica - In this paper, Sommerfeld effect of a non-ideal induction motor in a simple cantilever beam system is studied. On basis of fully considering the interaction between the beam structure...     

HNO3-Al（NO3）3溶液分离包头混合稀土精矿的研究

根据Al3+与F-能形成稳定的络合离子[AlF6]3-,采用HNO3-Al(NO3)3溶液络合浸出包头混合稀土精矿中的氟碳铈矿。热力学分析结果表明:HNO3-Al(NO3)3体系对稀土精矿浸出反应为自发过程。考察了HNO3浓度、Al(NO3)3浓度、液固比、搅拌速度、温度、搅拌时间这些因素对稀土精矿浸出的影响。实验结果表明:在HNO3浓度3 mol·L-1,Al(NO3)3浓度1.5 mol·L-1,液固比30∶1,搅拌速度300 r·min-1,温度100℃,搅拌时间90 min的条件下,稀土精矿中氟碳铈矿的浸出率达到92.18%,氟碳铈矿与独居石基本分离。通过产物层受界面交换和扩散混合控制的新缩小核模型可用来描述浸出过程的动力学,计算推导出了反应的宏观动力学方程。     

连续浮选机在稀土浮选中的应用研究

以验证稀土矿再精选工业化可行性为目的,通过采用XFLB型微型连续闭路浮选机进行一粗三扫三精的连续闭路试验方法,讨论了浮选时间、药剂加入量、浮选充气量、浮选机叶轮转速等因素对选矿指标和分选效率的影响规律,并根据原料矿物特殊性质对浮选时间修正系数进行了调整。实验结果:在流程稳定后,最终获得品位≥65%,回收率≥92%的稀土精矿。     

PrS0→Cr energy transfer and ESR investigation in Pr and Cr activated SrAl12O19 quantum cutting phosphor

With the help of the Dexter's theory, the energy transfer mechanism from Pr³⁺¹S₀ to Cr³⁺ is investigated theoretically in SrAl₁₂O₁₉:Pr³⁺, Cr³⁺ quantum cutting phosphors. The electron spin resonance (ESR) spectra of Pr³⁺ and Cr³⁺-doped SrAl₁₂O₁₉ with magnetoplumbite structure have been studied. The Cr³⁺ ion is found to enter the Al4(4f) site, which is very close to the Sr(2d) site replaced by the Pr³⁺ ions in the host. The theoretical results indicate that the efficient Pr³⁺¹S₀→Cr³⁺ energy transfer can only take place in the intermediate mirror planes, in which for the nearest and next-nearest Pr³⁺-Cr³⁺ pairs, both dipole-dipole and dipole-quadrupole interactions can play their parts in the transfer. Finally, an overview is given about the research on the energy transfer from Pr³⁺¹S₀ to codopants in their co-doped materials.     

Giant magnetoresistance of Co/ITO multilayers

The electrical and magnetic properties of Co/ITO multilayers with various ITO layer thickness are studied. Negative giant magnetoresistance with a maximum of −1.9% at room temperature and −2.57% at 15 K are observed. The magnitudes of GMR oscillate with a period of about 1 nm when varying the thickness of ITO layer.     

Near‐Infrared‐Light‐Induced Fast Drug Release Platform: Mesoporous Silica‐Coated Gold Nanoframes for Thermochemotherapy

Development of advanced theranostics for personalized medicine is of great interest. Herein, a multifunctional mesoporous silica‐based drug delivery carrier has been developed for efficient chemo/photothermal therapy. The unique Au nanoframes@mSiO₂ spheres are elaborately prepared by utilizing Ag@mSiO₂ yolk–shell spheres as the template through spatially confined galvanic replacement method. Compared with the Ag@mSiO₂ yolk–shell spheres, the resultant Au nanoframes@mSiO₂ spheres show a strong and broad near‐infrared (NIR) absorbance in the 550–1100 nm region, high surface areas, and good biocompatibility. When irradiated with a NIR laser with a power intensity of 1 W cm^?2 at 808 nm, they can become highly localized heat sources through the photothermal effect. Moreover, the photothermal effect of the Au nanoframes can significantly promote the fast release of doxorubicin. The in vitro studies show obvious synergistic effects combining photothermal therapy and chemotherapy in the Au nanoframes@mSiO₂ spheres against Hela cells. It is believed that the as‐obtained multifunctional vehicles provide a promising platform for the combination of hyperthermia and chemotherapy for cancer treatment application.