掺钕氟氧化物玻璃陶瓷的制备及表征

采用熔融和晶化技术合成出含CaF2微晶的Nd3+离子掺杂透明氟氧化物玻璃陶瓷材料, 并通过DTA, XRD, FEG-ESEM和UV-Vis-Nir分光光度计和傅里叶变换荧光光谱仪等对样品进行了表征. 结果表明, 玻璃陶瓷主晶相为CaF2, 晶相粒径为15 nm; 可见光透过率为78%~87%, 近红外透过率为84%~93%; 由于Nd3+在热处理后优先富集在具有低声子能量的CaF2晶相中, 从而改变了配体场, 使荧光谱线在1060 nm处的峰值比原始玻璃强度大.     

Chains of Rings with Local Formal Fibers

Let (T, M) be a complete local domain containing the integers. Let p ₁ ? p ₂ ? ··· ? p _n be a chain of nonmaximal prime ideals of T such that T _{p n} is a regular local ring. We construct a chain of excellent local domains A _n  ? A _n?1 ? ··· ? A ₁ such that for each 1 ≤ i ≤ n, the completion of A _i is T, the generic formal fiber of A _i is local with maximal ideal p _i , and if I is a nonzero ideal of A _i then A _i /I is complete. We then show that if Q is a nonmaximal prime ideal of T and 1 ≤ h = ht _T Q, then there is a chain of excellent local domains B ₀ ? B ₁ ? ··· ? B _h  ? T such that for every i = 0, 1, 2,…, h we have ht(Q ∩ B _i ) = i, the completion of B _i is isomorphic to T[[X ₁, X ₂,…, X _i ]] where the X _j 's are indeterminants, and the formal fiber of Q ∩ B _i is local.     

Infinite dimensional excellent rings

In this note, we prove that there exist infinite dimensional excellent rings.     

含叔丁基、醚键和双酚A单元可溶性聚酰亚胺的合成与表征

通过分子设计合成了一种含叔丁基、醚键和双酚A单元的二胺单体2,2-二(3'-叔丁基-4'-氨基二苯醚-4-基)丙烷(4),然后将其与4种商品化的芳香二酐单体:联苯四羧酸二酐(BPDA)、二苯醚四酸二酐(OPDA)、二苯六氟异丙基四酸二酐(6FDA)和均苯四酸二酐(PMDA)经高温"一步法"制备了一系列新型聚酰亚胺(PI)树脂,并对它们的结构与性能进行了研究.结果表明,该系列PI在NMP、DMF、DMAc、THF和CHCl3等普通有机溶剂中具有良好的溶解性;玻璃化转变温度Tg(DSC)在265~302℃之间,5%热失重温度(N2氛围)在519℃以上;在400~760 nm可见光波长范围内,具有优异的光学透明性,透光率约等于或大于90%;PI的数均分子量(Mn,GPC)在1.90×10~4~3.90×10~4范围内,分子量分布(PDI)介于2.63~4.63之间,X-射线衍射(XRD)结果表明所得PI为无定形聚合物,吸水率低于0.5%.叔丁基、醚键和双酚A单元同时引入具有协同效应,可提高PI的溶解性和透明性,并保持PI原有良好的热稳定性、机械性能和较低的吸水率.     

On Methods of Computer Graphics for Visualizing Densities

This article focuses on visualizing densities and density approximators. We develop the relationship between the isopleths, the gradient, and the surface normals for a density with two-dimensional support. We show that these form a trihedron. We also develop the algorithm for computing the surface normal for the isopleths of a density with three-dimensional support. With this information in hand, we discuss rendering and lighting models, contouring algorithms, stereoscopic display algorithms, and visual design considerations. We conclude with some examples and a discussion of our experiences in using rendering and lighting, transparency, stereoscopy, dynamic rotation, and dynamic thresholding techniques to visualize densities.     

Characteristics and self-cleaning effect of the transparent super-hydrophobic film having nanofibers array structures

Transparent super-hydrophobic films were fabricated using the PDMS method and silane process, based on anodization in phosphoric acid. Contact angle tests were performed to determine the contact angle of each film according to the anodizing time. Transmittance tests also were performed to obtain the transparency of each TPT (trimethylolpropane propoxylate triacrylate) replica film according to the anodizing time. The contact angle was determined by studying the drop shape, and the transmittance was measured using a UV-spectrometer. The contact angle increases with increasing anodizing time, because increasing pillar length can trap more air between the TPT replica film and a drop of water. The transmittance falls with increasing anodizing time because the increasing pillar length causes a scattering effect. This study shows that the pillar length and transparency are inversely proportional. The TPT replica film having nanofibers array structures was better than other films in aspect of self-cleaning by doing quantitative experimentation.     

TICT based fluorescent probe with excellent photostability for real-time and long-term imaging of lipid droplets

Lipid droplets (LDs) are dynamic organelles and involve in various physiological processes by regulation of the storage and metabolism of lipid molecules. The real-time and long-term imaging of LDs’ distribution and movement is critical for investigation of their biological functions. However, current LDs-targeted fluorescent probes suffer from low photostability and high background noise. To tackle these challenges, we herein reported that the red-emissive fluorescent probe DCQTB with twisted intramolecular charge transfer (TICT) characteristics can be used for wash-free imaging of LDs with advantages of fast cell penetration ability, high specificity, excellent photostability, and low phototoxicity. This LDs-specific fluorescent probe is thus promising for investigation of the biological functions of LDs.     

Diversity-oriented one-pot synthesis of furan based densely substituted biheteroaryls via isocyanide insertion

A facile and efficient acid-catalyzed cascade reaction for the synthesis of novel biheteroaryl structural motifs containing densely functionalized furans has been developed. The reaction sequence involves a Knoevenagel condensation of arylglyoxals with aroyl or heteroaroylacetonitrile and subsequently an isocyanide insertion via formal [4+1] cycloaddition followed by rapid [1,3]-H shift to afford uniquely decorated novel biheterocycles. Furthermore, the scope of the methodology was extended to diverse biheteroaryls by employing 3-(2-furyl)-3-oxopropanenitrile, 3-cyanoacetyl-1-methylindole, 3-oxo-3-(1H-pyrrol-2-yl)propanenitrile, 3-(1H-indol-3-yl)-3-oxopropanenitrile, 3-Oxo-3-(2-thienyl)propionitrile and benzoylacetonitriles.     

Vertical-slate-like MoS2 nanostructures on 3D-Ni-foam for binder-free,low-cost,and scalable solid-state symmetric supercapacitors

Here, we report binder-free vertical-slate-like MoS₂ nanostructures on 3D-Ni-Foam (VSL-MoS₂@3D-Ni foam) for low-cost high-performance solid-state symmetric supercapacitors (SSCs). The cost-effective, ecofriendly and scalable solvothermal method and its direct incorporation of VSL-MoS₂@3D-Ni-foam yield SSCs with excellent electrochemical properties with a wide potential window of 1.0?V. Furthermore, high specific capacitance of 34.1?F?g^?1 at a current density of 1.3?A?g^?1, an energy density of 4.7?W?h?kg^?1 at a high-power density of 650?W?kg^?1, and excellent stability with ～82.5% capacitance retention after 10,000 cycles were demonstrated even for SSCs with a binder free MoS₂ electrodes on 3D-Ni-foam. These excellent features of the SSCs with VSL-MoS₂@3D-Ni-foam substantiate their potential opportunity for future energy applications.