采用纳米技术巧制可扩缩的非易失性电池

电子技术开发商mPhase Technologies公司(位于美国康涅狄格州诺沃克)采用电湿技术和超疏水性纳米结构表面制作成功一款能够长久贮存且性能不会下降的非易失性电池样品。与采用机械触发的现有储能电池相比，基于该纳米技术的电池无须活动部件，而且批量生产的成本很低廉。     

Understanding external plasticization of melt extruded PHBV–wheat straw fibers biodegradable composites for food packaging

The objective of this work is to get further knowledge on the external plasticization mechanisms of melt extruded polyhydroxyl‐3‐butyrate‐co?3‐valerate (PHBV) when combined with wheat straw fibers (WSF). Different types of biodegradable substances, all authorized for food contact according to the European regulation, i.e., acetyltributyl citrate (ATBC), glycerol triacetate (GTA) and (PEG) at different molecular weights, were tested at different percentages (5, 10 and 20 wt %). Thermal and mechanical characterization of PHBV/plasticizer blends showed that a significant plasticizing effect was obtained using hydrophobic substances such as ATBC and GTA, with an increase of the elongation at break from 1.8% up to about 6% for an additive content of 10 wt %. However, the incorporation of WSF in plasticized PHBV led to a dramatic decrease in the elongation at break of composites, neutralizing the increase of this parameter by the addition of the plasticizers. The stress at break of plasticized films was also significantly decreased by the introduction of fibers. Such a loss of ductility was mainly explained by the occurrence of microscopic defects in the materials induced by the presence of fibers and to a poor adhesion at the fiber/matrix interface. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41611.     

Hydroxide-Bonding Strength Measurements for Space-Based Optical Missions

Optical contacting has long been used in interferometric experiments both on the ground and in space-based missions. Its optical clarity makes it an ideal method to joint materials of comparable coefficients of thermal expansion. Once the two pieces are bonded, they are commonly broken through thermal or vibrational cycling. Unfortunately, larger bond areas are needed for the bond to form appreciable strength, which often excludes it from being used in complex optical bench designs in space-based missions. Another method, known colloquially as hydroxide bonding, has shown to have superior strength to optical contacting using smaller bonding areas. In addition, the hydroxide bonding process will work on several materials that do not need to meet the stringent polishing requirements of optical contacting. These properties make hydroxide bonding suitable for complex optical bench designs that can withstand the large accelerations encountered during launch conditions for use in space-based missions. In this paper, we report on shear strength measurements of BK7-to-BK7 hydroxide bonds as well as present new results for BK7-to-silicon carbide and BK7-to-Super Invar bonds.     

光捕捉技术有望推进光电通信

普林斯顿大学的研究人员已经发现了制造准晶聚合物（quasicrystalline polymer）结构的方法，这代表了光子学潜在的重大进步。这种结构能够控制光的传播，使得光子通信系统成为可能。目前，在光子电路中，光不能进行锐角的转折，准晶点阵技术可使光在电路中传播时产生锐角转折，这将推动高速通信和计算设备的发展。     

Effect of stress and temperature on the micromechanics of creep in highly irradiated bone and dentin

Synchrotron X-ray diffraction is used to study in situ the evolution of phase strains during compressive creep deformation in bovine bone and dentin for a range of compressive stresses and irradiation rates, at ambient and body temperatures. In all cases, compressive strains in the collagen phase increase with increasing creep time (and concomitant irradiation), reflecting macroscopic deformation of the sample. By contrast, compressive elastic strains in the hydroxyapatite (HAP) phase, created upon initial application of compressive load on the sample, decrease with increasing time (and irradiation) for all conditions; this load shedding behavior is consistent with damage at the HAP–collagen interface due to the high irradiation doses (from ~ 100 to ~ 9,000 kGy). Both the HAP and fibril strain rates increase with applied compressive stress, temperature and irradiation rate, which is indicative of greater collagen molecular sliding at the HAP–collagen interface and greater intermolecular sliding (i.e., plastic deformation) within the collagen network. The temperature sensitivity confirms that testing at body temperature, rather than ambient temperature, is necessary to assess the in vivo behavior of bone and teeth. The characteristic pattern of HAP strain evolution with time differs quantitatively between bone and dentin, and may reflect their different structural organization.     

A rare form of total abnormal pulmonary stenosis return: atresia of the common pulmonary vein

One case of atresia of the common pulmonary vein is discussed at the light of the few reports found in the literature. The presence of criteria distinguishing this type of obstacle to pulmonary venous return from the other cases, is of practical diagnostic interest; indeed, its diagnosis leads to surgical intervention, theoretically curative.     

数字电源论坛展示实用化进展

会议的重点是电子系统中的数字电源管理及功率变换器中数字控制技术的运用     

19F NMR-Based Fragment Screening for 14 Different Biologically Active RNAs and 10 DNA and Protein Counter-Screens

We report here the nuclear magnetic resonance ¹⁹F screening of 14 RNA targets with different secondary and tertiary structure to systematically assess the druggability of RNAs. Our RNA targets include representative bacterial riboswitches that naturally bind with nanomolar affinity and high specificity to cellular metabolites of low molecular weight. Based on counter-screens against five DNAs and five proteins, we can show that RNA can be specifically targeted. To demonstrate the quality of the initial fragment library that has been designed for easy follow-up chemistry, we further show how to increase binding affinity from an initial fragment hit by chemistry that links the identified fragment to the intercalator acridine. Thus, we achieve low-micromolar binding affinity without losing binding specificity between two different terminator structures.