微棱镜逆反射材料特性分析及制作

对微棱镜逆反射材料进行了理论研究和实验制作.理论分析了微棱镜单元内光线的逆反射特性,并研究了全反射条件对入射孔径角的限制以及阵列结构的逆反射率.提出了一种新的工艺方法,用于制作大尺寸的微棱镜模版.该方法将小尺寸镍模版利用类似"盖章"的方法在较大尺寸的聚碳酸酯基底上依次压制并使其紧密排列,然后再利用电铸的方法生长出大尺寸镍工作模版.最终得到了尺寸为500 mm×100 mm的模版.使用其制作的样片的逆反射系数最高大于750 cd/(1x·m2).     

Fatty Acid,Lipid Class,and Phospholipid Molecular Species Composition of the Soft Coral Xenia sp. (Nha Trang Bay,the South China Sea,Vietnam)

The soft corals of the genus Xenia are common for Indo‐Pacific reef ecosystems. Lipid class, fatty acid (FA), phospho‐ and phosphonolipid molecular species compositions were identified for the first time in the soft coral Xenia sp. from Vietnam. Total lipids consisted predominantly of waxes, monoalkyl diacylglycerols, triacylglycerols, sterols, and polar lipids (21.4, 7.7, 14.2, 10.5, and 36.7 %, respectively). Sesquiterpene alcohol, valerenenol, was found. Acids 16:0, 18:3n‐6, 20:4n‐6, and 20:5n‐3 dominated in total FA. The markers of zooxanthellae (18:4n‐3 and 18:5n‐3) and octocorals (24:5n‐6 and 24:6n‐3) were detected. Acids 18:5n‐3, 20:4n‐6, 22:4n‐6, and 24:5n‐6 concentrated in FA of polar lipids, whereas 14:0, 16:0, 16:1n‐7, 18:2n‐6, and 18:3n‐6 were the major FA of neutral lipids. ChoGpl, EtnGpl, SerGpl, CAEP, PtdIns, and lyso ChoGpl constituted 39.5, 20.8, 20.5, 9.7, 4.3, and 5.3 %, respectively, of the sum of phospho‐ and phosphonolipids. Thirty‐two molecular species of phospholipids and ceramide aminoethylphosphonate (CAEP) were determined by high resolution tandem mass spectrometry. Lyso 18:0e PakCho (4.1 %), 18:0e/20:4 PakCho (20.5 %), 18:1e/20:4 PlsEtn (18.0 %), 18:0e/24:5 PakSer (14.0 %), and 16:0 CAEP (9.6 %) were the major molecular species. EtnGpl and PtdIns mainly consisted of alkenyl acyl and diacyl forms, respectively. Alkyl acyl forms predominated in ChoGpl and SerGpl. Acid 24:5n‐6 was a principal FA in SerGpl, whereas 20:4n‐6 was more abundant in ChoGpl and EtnGpl. PtdIns contained various C_20–24 PUFA. In the context of chemotaxonomy of corals, Xenia sp. has the lipid composition typical for soft corals and the FA profile similar to that of alcyonarians with the high level of 18:3n‐6.     

Multiple Antimicrobial Effects of Hybrid Peptides Synthesized Based on the Sequence of Ribosomal S1 Protein from Staphylococcus aureus

The need to develop new antimicrobial peptides is due to the high resistance of pathogenic bacteria to traditional antibiotics now and in the future. The creation of synthetic peptide constructs is a common and successful approach to the development of new antimicrobial peptides. In this work, we use a simple, flexible, and scalable technique to create hybrid antimicrobial peptides containing amyloidogenic regions of the ribosomal S1 protein from Staphylococcus aureus. While the cell-penetrating peptide allows the peptide to enter the bacterial cell, the amyloidogenic site provides an antimicrobial effect by coaggregating with functional bacterial proteins. We have demonstrated the antimicrobial effects of the R23F, R23DI, and R23EI hybrid peptides against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa, Escherichia coli, and Bacillus cereus. R23F, R23DI, and R23EI can be used as antimicrobial peptides against Gram-positive and Gram-negative bacteria resistant to traditional antibiotics.     

Characterization of silicon- and carbon-based composite anodes for lithium-ion batteries

In recent years development of active materials for negative electrodes has been of great interest. Special attention has been focused on the active materials possessing higher reversible capacity than that of conventional graphite. In the present work the electrochemical performance of some carbon/silicon-based materials has been analyzed. For this purpose various silicon-based composites were prepared using such carbon materials as graphite, hard carbon and graphitized carbon black. An analysis of charging-discharging processes at electrodes based on different carbon materials has shown that graphite modified with silicon is the most promising anode material. It has also been revealed that the irreversible capacity mainly depends on the content of Si. An optimum content of Si has been determined with taking into account that high irreversible capacity is not suitable for practical application in lithium-ion batteries. This content falls within the range of 8-10 wt%.The reversible capacity of graphite modified with 8 wt% carbon-coated Si was as high as 604 mAh g⁻¹. The irreversible capacity loss with this material was as low as 8.1%. The small irreversible capacity of the material allowed developing full lithium-ion rechargeable cells in the 2016 coin cell configuration. Lithium-ion batteries based on graphite modified with silicon show gravimetric and volumetric specific energy densities which are higher by approximately 20% than those for a lithium-ion battery based on natural graphite.     

Lithium-ion batteries based on carbon–silicon–graphite composite anodes

The paper is devoted to the development of lithium-ion battery grade negative electrode active materials with higher reversible capacity than that offered by conventional graphite. The authors report on results of their experiments as related to the electrochemical performance of silicon-based materials for lithium-ion batteries. A commercial grade of spherically shaped natural graphite (FormulaBT™ SLA1025) was modified in a number of different ways with nano-sized silicon. The reversible capacity of SLA1025 modified by 9.2 wt% of the nano-sized amorphous silicon was seen to be as high as 590 mAh g⁻¹. The irreversible capacity loss with this compound was 20%. Lithium-ion batteries using such material were observed to display sharp capacity decay during prolonged cycling. In contrast, the reversible capacity of another experimental grade, the SLA1025 modified by 7.9 wt% of the carbon-coated Si was as high as 604 mAh g⁻¹. The irreversible capacity loss with this material was as low as 8.1%. This grade, also, was seen to display much better cycling performance than the baseline natural graphite.     

Full-Swing Gate Diffusion Input logic—Case-study of low-power CLA adder design

Full Swing Gate Diffusion Input (FS-GDI) methodology is presented. The proposed methodology is applied to a 40 nm Carry Look Ahead Adder (CLA). The CLA is implemented mainly using GDI full-swing F1 and F2 gates, which are the counterparts of standard CMOS NAND and NOR gates. A 16-bit GDI CLA was designed in a 40 nm low power TSMC process. The CLA, implemented according to the proposed methodology, presents full functionality and robustness under global and local process variations at wide range of supply voltages. Simulation results show 2× area reduction, 5× improvement in dynamic energy dissipation and 4× decrease in leakage, with a slight (24%) degradation in performance, when compared to the CMOS CLA. Advanced design metrics of GDI cells, such as minimum energy point (MEP) operation and minimum leakage vector (MLV), are discussed.     

Endocytosis in the mouse oocyte and its contribution to cAMP signaling during meiotic arrest

Mammalian oocytes are arrested at prophase I of meiosis until a preovulatory surge of LH stimulates them to resume meiosis. Prior to the LH surge, high levels of cAMP within the oocyte maintain meiotic arrest; this cAMP is generated in the oocyte through the activity of the constitutively active, G(s)-coupled receptor, G-protein-coupled receptor 3 (GPR3) or GPR12. Activated GPRs are typically targeted for desensitization through receptor-mediated endocytosis, but a continuously high level of cAMP is needed for meiotic arrest. The aim of this study was to examine whether receptor-mediated endocytosis occurs in the mouse oocyte and whether this could affect the maintenance of meiotic arrest. We found that constitutive endocytosis occurs in the mouse oocyte. Inhibitors of receptor-mediated endocytosis, monodansylcadaverine and dynasore, inhibited the formation of early endosomes and completely inhibited spontaneous meiotic resumption. A red fluorescent protein-tagged GPR3 localized in the plasma membrane and within early endosomes in the oocyte, demonstrating that GPR3 is endocytosed. However, overexpression of G-protein receptor kinase 2 and β-arrestin-2 had only a modest effect on stimulating meiotic resumption, suggesting that these proteins do not play a major role in GPR3 endocytosis. Inhibition of endocytosis elevated cAMP levels within oocytes, suggesting that there is an accumulation of GPR3 at the plasma membrane. These results show that endocytosis occurs in the oocyte, leading to a decrease in cAMP production, and suggest that there is a balance between cAMP production and degradation in the arrested oocyte that maintains cAMP levels at an appropriate level during the maintenance of meiotic arrest.