פרסומים

2017
Tuning Product Selectivity by Changing the Size of Catalytically Active Metallic Nanoparticles

One of the grand challenges in catalysis research is to rationally design efficient catalysts with controllable product selectivity. This goal has become feasible by recent developments in synthesis of architecturally designed catalytic nanoparticles, with high control over their structural properties. Here, we review recent progress in the synthesis, reactivity, and characterization of metallic nanoparticles in the size range of 1–10 nm, specifically focusing on the impact of nanoparticles' size on product selectivity.

In the first part of this chapter, we discuss the ways by which changes in the nanoparticles' size modify its surface properties and as a consequence alter its catalytic selectivity in hydrogenation reactions. In the second part of the chapter, we show that the oxidation state of metallic nanoparticles can be tuned by decreasing their size below 2 nm. These changes in the electronic properties of the nanoparticles activate them toward a variety of organic reactions that have been mainly activated by homogeneous catalysts.

Throughout this chapter, we demonstrate that in situ characterization of the catalyst under reaction conditions can provide an in-depth analysis of the impact of nanoparticles' size on the reaction mechanism. In the last part of the chapter, we discuss the challenges and opportunities in the research field of size-dependent reactivity. Specifically, we address recent developments in the preparation, characterization, and reactivity of subnanometer metallic clusters.

Joana Salta, Benhamou, Raphael I. , Herzog, Ido M. , ו Fridman, Micha.. 2017. Tuning The Effects Of Bacterial Membrane Permeability Through Photo-Isomerization Of Antimicrobial Cationic Amphiphiles. Chemistry A European Journal, 23, 52, Pp. 12724–12728.
Reuven Amitai. 2017. Turks And Mongols. First, Pp. 311. Brill: Leiden.
Amit Gvaryahu. 2017. Twisting Words: Does Halakhah Really Circumvent Scripture?. Journal Of Jewish Studies, 68, Pp. 260-283. תקציר
abstract A foundational text in the study of Tannaitic Midrash and Halakhah, Sifre Deuteronomy 122 is a list of places where Halakhah ʿ qpt scripture. This word, ʿ qpt, has long been understood to mean ‘circumvent’, ‘bypass’ or ‘belie’, and the pericope has been read as a list of places where ‘Halakhah} circumvents scripture’, and thus a testament to the power of the accepted tradition to override the words of the Torah. Based on documentary and linguistic evidence, this article questions the interpretation of the word ʿ qpt and suggests that it means not ‘circumvent’ but rather ‘multiply’. As it does so, it also suggests a new meaning for the list, as a declaration of the limits of the Midrashic method of the Tannaitic school of Rabbi Ishmael, committed both to accepted traditions and to its more restrictive and systematic method of reading scripture.
B Helm, Visser, ME , Schwartz, W, Kronfeld-Schor, N, Gerkema, M, Piersma, T, ו Bloch, Guy . 2017. Two Sides Of A Coin: Ecological And Chronobiological Perspectives Of Timing In The Wild. Philosophical Transactions Of The Royal Society B, 20160246. . Publisher's Version תקציר
Most processes within organisms, and most interactions between organisms and their environment, have distinct time profiles. The temporal coordination of such processes is crucial across levels of biological organization, but diferent disciplines differ widely in their approaches to study timing. Such differences are accentuated between ecologists, who are centrally concerned with a holistic view of an organism in relation to its external environment, and chronobiologists, who emphasize internal timekeeping within an organism and the mechanisms of its adjustment to the environment. We argue that ecological and chronobiological perspectives are complementary, and that studies at the intersection will enable both fields to jointly overcome obstacles that currently hinder progress. However, to achieve this integration, we first have to cross some conceptual barriers, clarifying prohibitively inaccessible terminologies. We critically assess main assumptions and concepts in either field, as well as their common interests. Both approaches intersect in their need to understand the extent and regulation of temporal plasticity, and in the concept of ‘chronotype’, i.e. the characteristic temporal properties of individuals which are the targets of natural and sexual selection. We then highlight promising developments, point out open questions, acknowledge difficulties and propose directions for further integration of ecological and chronobiological perspectives through Wild Clock research.This article is part of the themed issue ‘Wild Clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals’.
Tom Wagner, Oded, Meirav , Shenhar, Roy , ו Böker, Alexander . 2017. Two-Dimensionally Ordered Aunp Array Formation Via Microcontact Printing On Lamellar Diblock Copolymer Films. Polymers For Advanced Technologies, 28, Pp. 623-628. doi:10.1002/pat.3853.
The construction of nano-sized, two-dimensionally ordered nanoparticle (NP) superstructures is important for various advanced applications such as photonics, sensing, catalysis, or nano-circuitry. Currently, such structures are fabricated using the templated organization approach, in which the templates are mainly created by photo-lithography or laser-lithography and other invasive top-down etching procedures. In this work, we present an alternative bottom-up preparation method for the controlled deposition of NPs into hierarchical structures. Lamellar polystyrene-block-poly(2-vinylpyridinium) thin films featuring alternating stripes of neutral PS and positively charged P2VP domains serve as templates, allowing for the selective adsorption of negatively charged gold NPs. Dense NP assembly is achieved by a simple immersion process, whereas two-dimensionally ordered arrays of NPs are realized by microcontact printing (mu CP), utilizing periodic polydimethylsiloxane wrinkle grooves loaded with gold NPs. This approach enables the facile construction of hierarchical NP arrays with variable geometries. Copyright (C) 2016 John Wiley & Sons, Ltd.
Griffin Hosseinzadeh, Arcavi, Iair , Valenti, Stefano , McCully, Curtis , D. Howell, Andrew , Johansson, Joel , Sollerman, Jesper , Pastorello, Andrea , Benetti, Stefano , Cao, Yi , S. Cenko, Bradley , Clubb, Kelsey I, Corsi, Alessandra , Duggan, Gina , Elias-Rosa, Nancy , Filippenko, Alexei V, Fox, Ori D, Fremling, Christoffer , Horesh, Assaf , Karamehmetoglu, Emir , Kasliwal, Mansi , Marion, G. H, Ofek, Eran , Sand, David , Taddia, Francesco , Zheng, WeiKang , Fraser, Morgan , Gal-Yam, Avishay , Inserra, Cosimo , Laher, Russ , Masci, Frank , Rebbapragada, Umaa , Smartt, Stephen , Smith, Ken W, Sullivan, Mark , Surace, Jason , ו Wozniak, Przemek . 2017. Type Ibn Supernovae Show Photometric Homogeneity And Spectral Diversity At Maximum Light. \Apj, 836, Pp. 158. doi:10.3847/1538-4357/836/2/158.
Igor Kreimerman. 2017. A Typology For Destruction Layers. The Late Bronze Age Southern Levant As A Case Study. בתוך Crisis To Collapse. The Archaeology Of Social Breakdown, Pp. 173–203. Presses universitaires de Louvain.
Yuval Ben-Shahar, Kriegel, Ilka , Scotognella, Francesco , Waiskopf, Nir , Dal Conte, Stefano , Moretti, Luca , Cerullo, Giulio , Rabani, Eran , ו Banin, Uri . 2017. Ultrafast Carrier Dynamics Unravel Role Of Surface Ligands And Metal Domain Size On The Photocatalytic Hydrogen Evolution Efficiency Of Au-Tipped Cds Nanorods: An Ultrafast Transient Absorption Spectroscopy Study. . Publisher's Version תקציר

Semiconductor-metal hybrid nanostructures are interesting materials for photocatalysis. Their tunable properties offer a highly controllable platform to design light-induced charge separation, a key to their function in photocatalytic water splitting. Hydrogen evolution quantum yields are influenced by factors as size, shape, material and morphology of the system, additionally the surface coating or the metal domain size play a dominant role.

 

In this paper we present a study on a well-defined model system of Au-tipped CdS nanorods. We use transient absorption spectroscopy to get insights into the charge carrier dynamics after photoexcitation of the bandgap of CdS nanorods. The study of charge transfer processes combined with the hydrogen evolution efficiency unravels the effects of surface coating and the gold tip size on the photocatalytic efficiency. Differences in efficiency with various surface ligands are primarily ascribed to the effects of surface passivation. Surface trapping of charge carriers is competing with effective charge separation, a prerequisite for photocatalysis, leading to the observed lower hydrogen production quantum yields. Interestingly, non-monotonic hydrogen evolution efficiency with size of the gold tip is observed, resulting in an optimal metal domain size for the most efficient photocatalysis. These results are explained by the sizedependent interplay of the metal domain charging and the relative band-alignments. Taken together our findings are of major importance for the potential application of hybrid nanoparticles as photocatalysts.

Liron Stern, Naiman, Alex , Keinan, Gal , Mazurski, Noa , Grajower, Meir , ו Levy, Uriel . 2017. Ultra-Precise Optical To Radio Frequency Based Chip-Scale Refractive Index And Temperature Sensor. Optica. doi:10.1364/optica.4.000001. תקציר
© 2017 Optical Society of America. Chip-scale high-precision measurements of physical quantities such as temperature, pressure, refractive index, and analytes have become common with nanophotonics and nanoplasmonics resonance cavities. Despite several important accomplishments, such optical sensors are still limited in their performances in the short and, in particular, long time regimes. Two major limitations are environmental fluctuations, which are imprinted on the measured signal, and the lack of miniaturized, scalable robust and precise methods of measuring optical frequencies directly. Here, by utilizing a frequency-locked loop combined with a reference resonator, we overcome these limitations and convert the measured signal from the optical domain to the radio-frequency domain. By doing so, we realize a highly precise on-chip sensing device with sensing precision approaching 10 −8 in effective refractive index units, and 90 $μ$K in temperature. Such an approach paves the way for single particle detection and high-precision chip-scale thermometry.
Sarah Genut ו Ben-David Kolikant, Yifat . 2017. Undergraduate Haredi Students Studying Computer Science: Is Their Prior Education Merely A Barrier?. Interdisciplinary Journal Of E-Skills And Lifelong Learning, 13, Pp. 197–214.
Omri M Finkel, Castrillo, Gabriel , Herrera Paredes, Sur , González, Isai Salas , ו Dangl, Jeffery L. 2017. Understanding And Exploiting Plant Beneficial Microbes. Current Opinion In Plant Biology, 38, Pp. 155–163.
J. Siev, Huppert, J.D. , ו Zuckerman, S.E.. 2017. Understanding And Treating Scrupulosity. בתוך J. Abramowitz, D. Mckay, & E. Storch (Eds.), Handbook Of Obsessive-Compulsive Disorder Across The Lifespan, Pp. 527-546. Wiley.
E. Flashner-Abramson, Heath, J. R, Levine, R. D, ו Kravchenko-Balasha, N.. 2017. Understanding Cancer Phenomena Using A Thermodynamic-Based Approach. European Biophysics Journal With Biophysics Letters, 46, Pp. S274-S274.
Dana Lassri, Luyten, Patrick , Fonagy, Peter , ו Shahar, Golan . 2017. Undetected Scars? Self-Criticism, Attachment, And Romantic Relationships Among Otherwise Well-Functioning Childhood Sexual Abuse Survivors. Psychological Trauma: Theory, Research, Practice, And Policy.
Y. Ophir, Asterhan, C. S. C. , ו Schwarz, B. B.. 2017. Unfolding The Notes From The Wall: Adolescents&Rsquo; Depression Manifestations On Facebook.. Computers In Human Behavior, 72, Pp. 96-107. . Publisher's Version
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J Papeer, Dey, I , Henis, Z , Botton, M , Ferber, Y , Kumar, GR , ו Zigler, A . 2017. Uniform Lifetime Prolongation Of A High Density Plasma Channel Left In The Wake Of Femtosecond Filament. Applied Physics Letters, 111.
Uniform Multilingualism: A Media Genealogy of Google Translate
Ido Ramati ו Pinchevski, Amit . 2017. Uniform Multilingualism: A Media Genealogy Of Google Translate. New Media & Society, 20, 7, Pp. 2550-2565. . Publisher's Version תקציר
This article applies a media geneaology perspective to examine the operative logic of Google Translate. Tracing machine translation from post–World War II (WWII) rule-based methods to contemporary algorithmic statistical methods, we analyze the underlying power structure of algorithmic and human collaboration that Translate encompasses. Focusing on the relationship between technology, language, and speakers, we argue that the operative logic of Translate represents a new model of translation, which we call uniform multilingualism. In this model, the manifest lingual plurality on the user side is mediated by lingual uniformity on the system side in the form of an English language algorithm, which has recently given way to an artificial neural network interlingual algorithm. We conclude by considering the significance of this recent shift in Translate’s algorithm.
Uniform multilingualism: A media genealogy of Google Translate