Riverside, CA, United States

University of California at Riverside

www.ucr.edu
Riverside, CA, United States

The University of California, Riverside , is a public research university and one of the 10 general campuses of the University of California system. The main campus sits on 1,900 acres in a suburban district of Riverside, California, United States, with a branch campus of 20 acres in Palm Desert. Founded in 1907 as the UC Citrus Experiment Station, Riverside pioneered research in biological pest control and the use of growth regulators responsible for extending the citrus growing season in California from four to nine months. Some of the world's most important research collections on citrus diversity and entomology, as well as science fiction and photography, are located at Riverside.UCR's undergraduate College of Letters and Science opened in 1954. The Regents of the University of California declared UCR a general campus of the system in 1959, and graduate students were admitted in 1961. To accommodate an enrollment of 21,000 students by 2015, more than $730 million has been invested in new construction projects since 1999. Preliminary accreditation of the UCR School of Medicine was granted in October 2012 and the first class of 50 students was enrolled in August 2013. It is the first new research-based public medical school in 40 years.UCR is consistently ranked as one of the most ethnically and economically diverse universities in the United States. The 2014 U.S. News & World Report Best Colleges rankings places UCR 55th among top public universities, 112th nationwide and ranks 16+ graduate school programs including the Graduate School of Education and the Bourns College of Engineering based on peer assessment, student selectivity, financial resources, and other factors. Washington Monthly ranked UCR 5th in the United States in terms of social mobility, research and community service, while U.S. News ranks UCR as the fifth most ethnically diverse and, by the number of undergraduates receiving Pell Grants , the 15th most economically diverse student body in the nation. Nearly two-thirds of all UCR students graduate within six years without regard to economic disparity. UCR's extensive outreach and retention programs have contributed to its reputation as a "campus of choice" for minority students, including LGBT students. In 2005, UCR became the first public university campus in the nation to offer a gender-neutral housing option.UCR's sports teams are known as the Highlanders and play in the Big West Conference of the National Collegiate Athletic Association Division I. Their nickname was inspired by the high altitude of the campus, which lies on the foothills of Box Springs Mountain. The UCR women's basketball team won back to back Big West championships in 2006 and 2007. In 2007, the men's baseball team won its first conference championship and advanced to the regionals for the second time since the university moved to Division I in 2001. Wikipedia.


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Balandin A.A.,University of California at Riverside
Nature Materials | Year: 2011

Recent years have seen a rapid growth of interest by the scientific and engineering communities in the thermal properties of materials. Heat removal has become a crucial issue for continuing progress in the electronic industry, and thermal conduction in low-dimensional structures has revealed truly intriguing features. Carbon allotropes and their derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range-of over five orders of magnitude-from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. Here, I review the thermal properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. Special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe the prospects of applications of graphene and carbon materials for thermal management of electronics. © 2011 Macmillan Publishers Limited. All rights reserved.


Reed C.A.,University of California at Riverside
Accounts of Chemical Research | Year: 2010

(Figure Presented) For decades, triflic acid, methyl triflate, and trialkylsilyl triflate reagents have served synthetic chemistry well as clean, strong electrophilic sources of H+, CH3 +, and R3Si+, respectively. However, a number of weakly basic substrates are unreactive toward these reagents. In addition, triflate anion can express undesired nucleophilicity toward electrophilically activated substrates. In this Account, we describe methods that replace triflatebased electrophilic reagents with carborane reagents. Using carborane anions of type CHB11R5X6 - (R = H, Me, X; X = Br, Cl), members of a class of notably inert, weakly nucleophilic anions, significantly increases the electrophilicity of these reagents and shuts down subsequent nucleophilic chemistry of the anion. Thus, H(carborane) acids cleanly protonate benzene, phosphabenzene, C60, etc., while triflic acid does not. Similarly, CH3 (carborane) reagents can methylate substrates that are inert to boiling neat methyl triflate, including benzene, phosphabenzenes, phosphazenes, and the pentamethylhydrazinium ion, which forms the dipositive ethane analogue, Me6N2 2+. Methyl carboranes are also surprisingly effective in abstracting hydride from simple alkanes to give isolable carbocation salts, e.g., t-butyl cation. Trialkylsilyl carborane reagents, R3Si(carborane), abstract halides from substrates to produce cations of unprecedented reactivity. For example, fluoride is extracted from freons to form carbocations; chloride is extracted from IrCl(CO) (PPh3)2 to form a coordinatively unsaturated iridium cation that undergoes oxidative addition with chlorobenzene at room temperature; and silylation of cyclo-N3P3Cl6 produces a catalyst for the polymerization of phosphazenes that functions at room temperature. Although currently too expensive for widespread use, carborane reagents are nevertheless of considerable interest as specialty reagents for making reactive cations and catalysts. © 2010 American Chemical Society.


Bardeen C.J.,University of California at Riverside
Annual Review of Physical Chemistry | Year: 2014

The photophysical behavior of organic semiconductors is governed by their excitonic states. In this review, I classify the three different exciton types (Frenkel singlet, Frenkel triplet, and charge transfer) typically encountered in organic semiconductors. Experimental challenges that arise in the study of solid-state organic systems are discussed. The steady-state spectroscopy of intermolecular delocalized Frenkel excitons is described, using crystalline tetracene as an example. I consider the problem of a localized exciton diffusing in a disordered matrix in detail, and experimental results on conjugated polymers and model systems suggest that energetic disorder leads to subdiffusive motion. Multiexciton processes such as singlet fission and triplet fusion are described, emphasizing the role of spin state coherence and magnetic fields in studying singlet ↔ triplet pair interconversion. Singlet fission provides an example of how all three types of excitons (triplet, singlet, and charge transfer) may interact to produce useful phenomena for applications such as solar energy conversion. Copyright © 2014 by Annual Reviews.


Zaera F.,University of California at Riverside
Chemical Reviews | Year: 2012

A study was conducted to demonstrate probing techniques for liquid and solid interfaces at the molecular level. Investigations revealed that new approaches were needed to study liquid or solid interfaces at a molecular level. Some electron-based surface-science techniques were adapted to probe liquid and solid interfaces by minimizing the paths that the probing particles needed to travel through the liquid phase. The use of techniques based on light or other electromagnetic radiation for surface analysis had more potential to achieve these objectives. The potential use of techniques, such as X-ray photoelectron spectroscopy and nuclear magnetic and electron spin resonance spectroscopies for the characterization of liquid and solid interfaces was investigated. Investigations revealed that infrared (IR) absorption spectroscopy was the most commonly used technique for the molecular-level characterization of such liquid and solid interfaces.


Zaera F.,University of California at Riverside
Chemical Society Reviews | Year: 2014

Infrared absorption spectroscopy has proven to be one of the most powerful spectroscopic techniques available for the characterization of catalytic systems. Although the history of IR absorption spectroscopy in catalysis is long, the technique continues to provide key fundamental information about a variety of catalysts and catalytic reactions, and to also offer novel options for the acquisition of new information on both reaction mechanisms and the nature of the solids used as catalysts. In this review, an overview is provided of the main contributions that have been derived from IR absorption spectroscopy studies of catalytic systems, and a discussion is included on new trends and new potential directions of research involving IR in catalysis. We start by briefly describing the power of Fourier-transform IR (FTIR) instruments and the main experimental IR setups available, namely, transmission (TIR), diffuse reflectance (DRIFTS), attenuated total reflection (ATR-IR), and reflection-absorption (RAIRS), for advancing research in catalysis. We then discuss the different environments under which IR characterization of catalysts is carried out, including in situ and operando studies of typical catalytic processes in gas-phase, research with model catalysts in ultrahigh vacuum (UHV) and so-called high-pressure cell instruments, and work involving liquid/solid interfaces. A presentation of the type of information extracted from IR data follows in terms of the identification of adsorbed intermediates, the characterization of the surfaces of the catalysts themselves, the quantitation of IR intensities to extract surface coverages, and the use of probe molecules to identify and titrate specific catalytic sites. Finally, the different options for carrying out kinetic studies with temporal resolution such as rapid-scan FTIR, step-scan FTIR, and the use of tunable lasers or synchrotron sources, and to obtain spatially resolved spectra, by sample rastering or by 2D imaging, are introduced. © the Partner Organisations 2014.


Bartels L.,University of California at Riverside
Nature Chemistry | Year: 2010

The design of networks of organic molecules at metal surfaces, highly attractive for a variety of applications ranging from molecular electronics to gas sensors to protective coatings, has matured to a degree that patterns with multinanometre unit cells and almost any arbitrary geometry can be fabricated. This Review provides an overview of vacuum-deposited organic networks at metal surfaces, using intermolecular hydrogen bonding, metal-atom coordination and in situ polymerization. Recent progress in these areas highlights how the design of surface patterns can benefit from the wealth of information available from solution- and bulk-phase chemistry, while at the same time providing novel insights into the nature of such bonds through the applicability of direct scanning probe imaging at metal surfaces. © 2010 Macmillan Publishers Limited. All rights reserved.


Reed C.A.,University of California at Riverside
Accounts of Chemical Research | Year: 2013

Recent research has taught us that most protonated species are decidedly not well represented by a simple proton addition. What is the actual nature of the hydrogen ion (the "proton") when H+, HA, H 2A+, and so forth are written in formulas, chemical equations, and acid catalyzed reactions? In condensed media, H+ must be solvated and is nearly always dicoordinate, as illustrated by isolable bisdiethyletherate salts having H(OEt2)2 + cations and weakly coordinating anions. Even carbocations such as protonated alkenes have significant C-H···anion hydrogen bonding that gives the active protons two-coordinate character.Hydrogen bonding is everywhere, particularly when acids are involved. In contrast to the normal, asymmetric O-H···O hydrogen bonding found in water, ice, and proteins, short, strong, low-barrier (SSLB) H-bonding commonly appears when strong acids are present. Unusually low frequency IR νOHO bands are a good indicator of SSLB H-bonds, and curiously, bands associated with group vibrations near H+ in low-barrier H-bonding often disappear from the IR spectrum.Writing H3O+ (the Eigen ion), as often appears in textbooks, might seem more realistic than H+ for an ionized acid in water. However, this, too, is an unrealistic description of H (aq) +. The dihydrated H+ in the H 5O2 + cation (the Zundel ion) gets somewhat closer but still fails to rationalize all the experimental and computational data on H(aq) +. Researchers do not understand the broad swath of IR absorption from H(aq) +, known as the "continuous broad absorption" (cba). Theory has not reproduced the cba, but it appears to be the signature of delocalized protons whose motion is faster than the IR time scale. What does this mean for reaction mechanisms involving H(aq) +?For the past decade, the carborane acid H(CHB11Cl11) has been the strongest known Brønsted acid. (It is now surpassed by the fluorinated analogue H(CHB11F 11).) Carborane acids are strong enough to protonate alkanes at room temperature, giving H2 and carbocations. They protonate chloroalkanes to give dialkylchloronium ions, which decay to carbocations. By partially protonating an oxonium cation, they get as close to the fabled H 4O2+ ion as can be achieved outside of a computer. © 2013 American Chemical Society.


Bailey-Serres J.,University of California at Riverside
Annual Review of Plant Biology | Year: 2013

The expression of nuclear protein-coding genes is controlled by dynamic mechanisms ranging from DNA methylation, chromatin modification, and gene transcription to mRNA maturation, turnover, and translation and the posttranslational control of protein function. A genome-scale assessment of the spatiotemporal regulation of gene expression is essential for a comprehensive understanding of gene regulatory networks. However, there are major obstacles to the precise evaluation of gene regulation in multicellular plant organs; these include the monitoring of regulatory processes at levels other than steady-state transcript abundance, resolution of gene regulation in individual cells or cell types, and effective assessment of transient gene activity manifested during development or in response to external cues. This review surveys the advantages and applications of microgenomics technologies that enable panoramic quantitation of cell-type-specific expression in plants, focusing on the importance of querying gene activity at multiple steps in the continuum, from histone modification to selective translation. © Copyright ©2013 by Annual Reviews. All rights reserved.


Hare J.D.,University of California at Riverside
Annual Review of Entomology | Year: 2011

Plants often release a blend of volatile organic compounds in response to damage by herbivorous insects that may serve as cues to locate those herbivores by natural enemies. The blend of compounds emitted by plants may be more variable than is generally assumed. The quantity and the composition of the blends may vary with the species of the herbivore, the plant species and genotype within species, the environmental conditions under which plants are grown, and the number of herbivore species attacking the plant. Although it is often assumed that induced emission of these compounds is an adaptive tactic on the part of plants, the evidence that such responses minimize fitness losses of plants remains sparse because the necessary data on plant fitness rarely have been collected. The application of techniques of evolutionary quantitative genetics may facilitate the testing of widely held hypotheses about the evolution of induced production of volatile compounds under natural conditions. © 2011 by Annual Reviews. All rights reserved.


Balandin A.A.,University of California at Riverside
Nature Nanotechnology | Year: 2013

Low-frequency noise with a spectral density that depends inversely on frequency has been observed in a wide variety of systems including current fluctuations in resistors, intensity fluctuations in music and signals in human cognition. In electronics, the phenomenon, which is known as 1/f noise, flicker noise or excess noise, hampers the operation of numerous devices and circuits, and can be a significant impediment to the development of practical applications from new materials. Graphene offers unique opportunities for studying 1/f noise because of its two-dimensional structure and widely tunable two-dimensional carrier concentration. The creation of practical graphene-based devices will also depend on our ability to understand and control the low-frequency noise in this material system. Here, the characteristic features of 1/f noise in graphene and few-layer graphene are reviewed, and the implications of such noise for the development of graphene-based electronics including high-frequency devices and sensors are examined. © 2013 Macmillan Publishers Limited. All rights reserved.

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