三维七向编织结构细观分析

根据三维编织的主要工艺, 系统地分析了三维七向编织物纱线的面内和空间运动规律。在此基础上,建立了能反映其基本结构的几何单胞模型, 并推导了编织参数之间的数学关系, 为进一步分析三维七向编织复合材料的力学性能奠定了基础。      

Evidence for η6 Coordination to a Fullerene

Evidence for the first η⁶ derivative of a fullerene, [MoC₆₀F₁₈(CO)₃] has been obtained from reaction between [Mo(CH₃CN)₃(CO)₃] and C₆₀F₁₈.     

超音速火焰喷涂制备纳米和微米结构WC-η涂层的耐熔锌腐蚀性能

以钨氧化物、钴氧化物和炭黑为原料, 通过原位还原碳化反应制备纳米WC-η(η为Co₃W₃C、Co₆W₆C等缺碳相)复合粉, 粉末平均粒径为155 nm。该复合粉经团聚造粒制备得到具有高致密性和良好流动性的热喷涂粉末。以此纳米结构和商业化的微米结构低碳WC-12Co粉末作为喂料, 通过超音速火焰喷涂制备硬质合金涂层。结果表明, 纳米结构涂层中生成了一定量等轴状的W₂C相, 裂纹主要沿晶界或相界面扩展, 而微米结构涂层中除W₂C外还含有较多的W相, 主要包裹在WC颗粒表面, 穿晶断裂比例较高, 裂纹扩展路径较平滑。由于纳米结构涂层组织致密、晶粒细小、界面积大, 因此比微米结构涂层具有更高的硬度和断裂韧性。两种涂层在熔融锌液中浸泡200 h后, 微米结构涂层中产生了较多的横向和纵向裂纹, 导致材料的大面积剥落和基材腐蚀; 纳米结构涂层中没有发生锌的浸蚀, 在局部产生了少量纵向裂纹, 裂纹间隙被钨钴氧化物所填充, 反而抑制了熔锌对涂层的腐蚀, 因此纳米结构涂层表现出更高的耐熔锌腐蚀性能。     

Incorporating Runs Rules into Hotelling's χ2 Control Charts

This paper illustrates a simple and effective method of incorporating runs rules into Hotelling χ² control charts. A Markov chain will be used to obtain a desired in-control average run length (ARL). Comparisons between the basic multivariate χ² control chart and the multivariate χ² control chart, which incorporates the various runs rules, are based on their respective ARL performances. All multivariate χ² control charts that incorporate the various runs rules have shown better ARL performance compared to the basic multivariate χ² control chart for small shifts in distance λ from the in-control mean vector μ₀ to the out-of-control mean vector μ_s. An example of the application, based on the proposed method, is also given.     

A Performance Analysis of Hotelling's χ2 Control Chart with Supplementary Runs Rules

Hotelling's control chart is widely employed to control several related characteristics of a process because of its simplicity. However, it has little power when detecting small or moderate process shifts. The use of supplementary runs rules is described in this article showing the average run length improvements achieved and the runs rules appearance frequency.     

MgO·1.5Al2O3透明陶瓷的无压/热等静压烧结制备

镁铝尖晶石透明陶瓷是典型的结构功能一体化材料, 具有优异的光学和机械性能。实验合成了颗粒细小、均匀的单相MgO·1.5Al₂O₃陶瓷粉末, 并且利用XRD全谱拟合软件Fullprof和尖晶石位置分配程序SIDR两步法确定其晶体结构为(Mg_0.46Al_0.54)^IV[Mg_0.26Al_1.64□_0.09]^VIO₄。再通过真空无压烧结结合热等静压烧结制备出了高性能的透明陶瓷, 热等静压18 MPa下1850℃烧结4 h所得样品的致密度达到99.75%, 厚度为2 mm的烧结样品可见光透过率达到65%, 红外波段透过率达到80%以上, 维氏硬度为(12.75±0.12) GPa, 杨氏模量为277 GPa。     

Cu7S4 Nanosuperlattices with Greatly Enhanced Photothermal Efficiency

According to the simulation, the self‐assembly of Cu₇S₄ nanocrystals would enhance the photothermal conversion efficiency (PCE) because of the localized surface plasmon resonance effects, which is highly desirable for photothermal therapy (PTT). A new strategy to synthesize Cu₇S₄ nanosuperlattices with greatly enhanced PCE up to 65.7% under irradiation of 808 nm near infrared light is reported here. By tuning the surface properties of Cu₇S₄ nanocrystals during the synthesis via thermolysis of a new single precursor, dispersed nanoparticles (NPs), rod‐like alignments, and nanosuperlattices are obtained, respectively. To explore their PTT applications, these hydrophobic nanostructures are transferred into water by coating with home‐made amphiphilic polymer while maintaining their original structures. Under identical conditions, the PCE are 48.62% and 56.32% for dispersed NPs and rod‐like alignments, respectively. As expected, when the nanoparticles are self‐assembled into nanosuperlattices, the PCE is greatly enhanced up to 65.7%. This strong PCE, along with their excellent photothermal stability and good biocompatibility, renders these nanosuperlattices good candidates as PTT agents. In vitro photothermal ablation performances have undoubtedly proved the excellent PCE of our Cu₇S₄ nanosuperlattices. This research offers a versatile and effective solution to get PTT agents with high photothermal efficiency.     

Insights into mucosal innate responses to Escherichia coli O157 : H7 colonization of cattle by mathematical modelling of excretion dynamics

Mathematical model-based statistical inference applied to within-host dynamics of infectious diseases can help dissect complex interactions between hosts and microbes. This work has applied advances in model-based inference to understand colonization of cattle by enterohaemorrhagic Escherichia coli O157 : H7 at the terminal rectum. A mathematical model was developed based on niche replication and transition rates at this site. A nested-model comparison, applied to excretion curves from 25 calves, was used to reduce complexity while maintaining integrity. We conclude that, 5–9 days post inoculation, the innate immune response negates bacterial replication on the epithelium and either reduces attachment to or increases detachment from the epithelium of the terminal rectum. Thus, we provide a broadly applicable model that gives novel insights into bacterial replication rates in vivo and the timing and impact of host responses.     

亚微米级Ti4O7的制备及其光热转换性能

光热转换是一种有效的太阳能利用技术,其效率主要取决于光热转换材料的光吸收能力。本研究通过低成本球磨法制备亚微米级的Ti₄O₇,采用扫描电镜、激光粒度仪、X射线衍射仪、差式扫描热分析仪表征其微观形貌、粒径大小、组成和比热容,用紫外-可见-近红外(UV-Vis-NIR)分光光度计和太阳光模拟器分别测试其光吸收能力和光热转换性能。结果表明,通过球磨法成功制备出粒径约0.35 μm的亚微米Ti₄O₇粉末,其太阳光全光谱吸收能力约89.5%,光热转换效率约73.7%。当亚微米级Ti₄O₇漂浮在水面时,太阳光水蒸汽产生效率提高至无光热材料条件下的2.15倍。因此,亚微米级的Ti₄O₇作为光热转换材料具有很大应用潜力。     

Molecular encapsulation of thalidomide with sulfobutyl ether-7 beta-cyclodextrin for immediate release property: enhanced in vivo antitumor and antiangiogenesis efficacy in mice

Thalidomide's reported ability to inhibit tumor angiogenesis has led to clinical trials determining its effectiveness in combating various types of cancer. Since thalidomide exhibits low oral bioavailability due to limitations in solubility, inclusion complexation using sulfobutyl ether-7 β-cyclodextrin was used to improve the delivery of thalidomide. Our main goals were to increase the solubility, bioavailability as well as chemical stability of thalidomide through complexation with anionic β-cyclodextrin, to characterize the complex in solid state using differential scanning calorimetry, X-ray powder diffractometry, and to explore thalidomide's antitumorigenic and antiangiogenesis potential when administered orally as free and in combination with cyclodextrin to experimental animals. The aqueous solubility and aqueous alkaline stability of thalidomide was markedly increased by the SBE7βCD complexation. Thalidomide administered orally in combination with SBE7βCD, led to a significant delay in tumor formation as a result of improved cellular drug absorption, distribution through solubilization in experimental animals. The improved pharmacological efficacy of the thalidomide-cyclodextrin complex compared to free thalidomide in mouse melanoma model suggest that such a delivery system may be useful for the improved therapeutics of thalidomide, in vivo.     

Plasmon Enhanced Direct Bandgap Emissions in Cu7S4@Au2S@Au Nanorings

Nanostructured copper sulfides, promising earth‐abundant p‐type semiconductors, have found applications in a wide range of fields due to their versatility, tunable low bandgap, and environmental sustainability. The synthesis of hexagonal Cu₇S₄@Au₂S@Au nanorings exhibiting plasmon enhanced emissions at the direct bandgap is reported. The synthesized Cu₇S₄@Au₂S@Au nanorings show greatly enhanced absorption and emission by local plasmons compared to pure copper sulfide nanoparticles.     

Cover Picture: Length‐Dependent Uptake of DNA‐Wrapped Single‐Walled Carbon Nanotubes (Adv. Mater. 7/2007)

Well‐defined length fractions of DNA‐wrapped single‐walled carbon nanotubes (SWNTs) of below 200 nm are taken up preferentially by IMR‐90 human lung fibroblasts, while longer DNA wrapped SWNTs are excluded from the cell interior (inset), report Matt Becker and coworkers on p. 939. The cover image construct includes overlaid images of the labeled cell membrane, the nuclei (blue), and the fluorescently labeled DNA wrapped SWNTs (red) that have gained access to the cell interior.     

C6A4MS与C11A7.CaF2的共存与转化关系研究

本文详细研究了C6 A4 MS与C11 A7.CaF2的共存与转化条件。结果表明：C11 A7.CaF2含量较高时能够抑制C6 A4 MS的形成，含量较低时则能与C6 A4 MS共存；升高温度能够消除C11 A7.CaF2对C6 A4 MS的形成的影响；C11 A7.CaF2能与合成矿物C6 A4 MS共存。，The coexistence and transformation condition between C6 A4 MS and C11 A7 . CaF2 is studied in detail in this paper. The results shows that C11 A7 . CaF2 can restrain the formation of C6 A4 MS when in higher content, but It can coexist with C6 A4 MS when its concentration is lower. Increasing temperature can avoid the effect of C11 A7 . CaF2 on the formation of C6 A4 MS. C11 A7 . CaF2 can coexist with syntheitical mineral C6 A4 MS.     

Mechanical Exfoliation of Select MAX Phases and Mo4Ce4Al7C3 Single Crystals to Produce MAXenes

MXenes—2D carbides/nitrides derived from their bulk nanolamellar M_n+1AX_n phase (MAX) counterparts—are, for the most part, obtained by chemical etching. Despite the fact that the M? A bonds in the MAX phases are not weak, in this work it is demonstrated that relatively large MAX single crystals can be mechanically exfoliated using the adhesive tape method to produce flakes whose thickness can be reduced down to half a unit cell. The exfoliated flakes, transferred onto SiO₂/Si substrates, are analyzed using electric force microscopy (EFM). No appreciable variation in EFM signal with flake thickness is found. EFM contrast between the flakes and SiO₂ not only depends on the contact surface potential, but also on the local capacitance. The contribution of the latter can be used to show the metallic character—confirmed by four‐contact resistivity measurements—of even the thinnest of flakes. Because the A‐layers are preserved, strictly speaking MXenes are not dealt with in this work, but rather MAXenes. This is important in the case where the “A” layers contain magnetic elements such as Mo₄Ce₄Al₇C₃, whose structure is a derivative of the MAX structure.     

解析GRACoL 7通用商业平版胶印工艺要求规范及G7工艺规程

通过对GRACoL 7通用商业平版胶印工艺要求规范及G7工艺规程的研讨,有利于今后开展对此类标准的进一步研究与完善.新的GRACoL 7通用商业平版胶印工艺要求规范及C7工艺规程所涉及的新的参变量、新概念对于印刷工艺过程控制具有其优势和特点,具有相应的策略及战略考虑.这些参变量包括高光范围(HR)、绝对高光范围、中性印刷密度曲线(NPDC)、灰平衡等;GRACoL7通用商业平版胶印工艺要求规范及G7工艺规程对其它印刷标准或规范,如SWOP规范和ISO标准等具有一定的影响.研究表明:GRACoL规范仍需要考虑进一步的改进.