bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Redox‐Active Bridging Ligand to Promote Spin Delocalization, High‐Spin Complexes, and Magnetic Multi‐Switchability
Authors: Ma Xiaozhou , Suturina Elizaveta A. , De Siddhartha , Négrier Philippe , Rouzières Mathieu , Clérac Rodolphe , Dechambenoit Pierre 
Published: May 2018

AbstractA dinuclear CoII complex, [Co2(tphz)(tpy)2]n+ (n=4, 3 or 2; tphz: tetrapyridophenazine; tpy: terpyridine), has been assembled using the redox‐active and strongly complexing tphz bridging ligand. The magnetic properties of this complex can be tuned from spin‐crossover with T1/2≈470 K for the pristine compound (n=4) to single‐molecule magnet with an ST=5/2 spin ground state when once reduced (n=3) to finally a diamagnetic species when twice reduced (n=2). The two successive and reversible reductions are concomitant with an increase of the spin delocalization within the complex, promoting remarkably large magnetic exchange couplings and high‐spin species even at room temperature.
Experimental study of the combustion and NO emission behaviors during cofiring coal and biomass in O2/N2 and O2/H2O
Authors: Li Yuan , Zhou Hao , Li Ning , Tao Chengfei , Liu Zihua , Cen Kefa 
Published: May 2018

AbstractOxy‐H2O is considered to be a new generation of carbon capture and storage technology. The combustion and NO emission behaviors during co‐combustion in O2/N2 and O2/H2O were studied simultaneously in an isothermal thermogravimetric system, including the influence of blending ratio, coal type, biomass type, and oxygen concentration. The results show that replacing N2 by H2O accelerates the burning rate of a blend significantly and reduces the NO emission obviously. In O2/N2 and O2/H2O, blending biomass improves the burning rate and reduces the NO emission. The improvement of H2O on burning rate becomes weak with increasing blending ratio. There is an interactive effect on NO emission during co‐combustion in both atmospheres. For cofiring bituminous coal and poplar wood, the NO yield decreases with increasing blending ratio, whereas the NO conversion ratio increases in both atmospheres. As different coal ranks blend with a certain biomass, the blend with a higher coal rank results in a more obvious improvement of burning rate and a higher NO conversion ratio in both atmospheres. As a coal blends with different biofuels, a higher volatile biofuel leads to a higher burning rate in O2/N2, whereas this behavior is not obvious in O2/H2O. Blending coal with a higher nitrogen biofuel results in a lower NO conversion ratio in both atmospheres. In both atmospheres, the burning rate and NO conversion ratio of a blend both increase, as the oxygen concentration increases from 21% to 30%. The results provide direct guidance for the application of co‐combustion in O2/H2O.
Palladium‐Catalyzed Divergent Arylation of Triazolopyridines: A Computational Study
Authors: AbuSalim Deyaa I. , Hong Sungwoo , Baik Mu‐Hyun 
Published: May 2018

AbstractThe mechanisms for new palladium‐catalyzed divergent reactions of triazolopyridines were investigated by means of DFT calculations. Previously, it was observed experimentally that cross‐coupling at the C7‐position of triazolopyridines occurred when a strong base was used, whereas the reaction could be diverted to the C3‐position if a weak base was employed. Calculations suggest that a strong base, such as tert‐butoxide, can easily deprotonate C7−H, independent of the palladium metal, and deliver the preactivated substrate to palladium, which can reductively eliminate the final product. Without a strong base, the palladium(II) center reacts with the ring‐opened diazo imine isomer of triazolopyridine to initially form a palladium(II)–carbene intermediate, which undergoes migratory insertion followed by β‐hydride elimination to afford a 1,1‐disubstituted alkene.
Tetrafluorination of Aromatic Azide Yields a Highly Efficient Staudinger Reaction: Kinetics and Biolabeling
Authors: Xie Yonghui , Cheng Longhuai , Gao Yasi , Cai Xuekang , Yang Xing , Yi Long , Xi Zhen 
Published: May 2018

AbstractThe development of highly efficient bioorthogonal reactions is of paramount importance for the research fields of biomaterials and chemical biology. We found that the o,o′‐difluorinated aromatic azide was able to react with triphenylphosphine to produce water‐stable phosphanimine. To further improve the efficiency of this kind of nonhydrolysis Staudinger reaction, a tetrafluorinated aromatic azide was employed to develop a faster nonhydrolysis Staudinger reaction with a rate of up to 51 m−1 s−1, as revealed by high‐performance liquid chromatography (HPLC) analysis and fluorescence kinetics. As a proof‐of‐concept study, the highly efficient Staudinger reaction was successfully used for chemoselective fluorescence labeling of proteins and nucleic acids (DNA and RNA) as well as for protein polyethyleneglycol (PEG)ylation. We believe that this bioorthogonal reaction can provide a broadly useful tool for various bioconjugations.
Mixing Halogens To Assemble an All‐Inorganic Layered Perovskite with Warm White‐Light Emission
Authors: Li Xianfeng , Wang Sasa , Zhao Sangen , Li Lina , Li Yanqiang , Zhao Bingqing , Shen Yaoguo , Wu Zhenyue , Shan Pai , Luo Junhua 
Published: May 2018

AbstractMost of single‐component white‐light‐emitting materials focus on organic–inorganic hybrid perovskites, metal–organic frameworks, as well as all‐inorganic semiconductors. In this work, we successfully assembled an all‐inorganic layered perovskite by mixing two halogens of distinct ionic radii, namely, Rb2CdCl2I2, which emits “warm” white light with a high color rendering index of 88. To date, Rb2CdCl2I2 is the first single‐component white‐light‐emitting material with an all‐inorganic layered perovskite structure. Furthermore, Rb2CdCl2I2 is thermally highly stable up to 575 K. A series of luminescence measurements show that the white‐light emission arises from the lattice deformation, which are closely related to the [CdCl4I2]2− octahedra with high distortion from the distinct ionic radii of Cl and I. The first‐principles calculations reveal that both the Cl and I components make significant contributions to the electronic band structures of Rb2CdCl2I2. These findings indicate that mixing halogens is an effective route to design and synthesize new single‐component white‐light‐emitting materials.
Incorporating Energetic Moieties into Four Oxadiazole Ring Systems for the Generation of High‐Performance Energetic Materials
Authors: Wang Bohan , Xiong Hualin , Cheng Guangbin , Yang Hongwei 
Published: May 2018

AbstractThe synthesis of three neutral 3,3′‐di(1,2,5‐oxadiazol‐3‐yl)‐5,5′‐bi(1,2,4‐oxadiazole) structures in combination with different energetic moieties such as nitramino, trinitroethylamino, and N‐nitrated trinitroethylamino is presented. In addition, a novel family of energetic salts based on 4,4′‐([5,5′‐bi(1,2,4‐oxadiazole)]‐3,3′‐diyl)‐bis(1,2,5‐oxadiazol‐3‐nitramide) is synthesized. The new compounds (4, 6–18) are characterized by IR and multinuclear NMR spectroscopy and elemental analysis. The structures of 4⋅2 C4H8O2, 9, 13, 15, and 16 are further confirmed by single‐crystal X‐ray diffraction studies. The thermal stabilities of 4 and 6–18 are determined by differential scanning calorimetry. Most of the new compounds have high densities (1.72–1.93 g cm−3) measured using a gas pycnometer (25 °C). Energetic evaluation indicates that they also have good detonation pressures and velocities (P: 26.4–41.9 GPa; D: 8218–9550 m s−1).
Potential‐Dependent, Switchable Ion Selectivity in Aqueous Media Using Titanium Disulfide
Authors: Srimuk Pattarachai , Lee Juhan , Fleischmann Simon , Aslan Mesut , Kim Choonsoo , Presser Volker 
Published: May 2018

AbstractThe selective removal of ions by an electrochemical process is a promising approach to enable various water‐treatment applications such as water softening or heavy‐metal removal. Ion intercalation materials have been investigated for their intrinsic ability to prefer one specific ion over others, showing a preference for (small) monovalent ions over multivalent species. In this work, we present a fundamentally different approach: tunable ion selectivity not by modifying the electrode material, but by changing the operational voltage. We used titanium disulfide, which shows distinctly different potentials for the intercalation of different cations and formed binder‐free composite electrodes with carbon nanotubes. Capitalizing on this potential difference, we demonstrated controllable cation selectivity by online monitoring the effluent stream during electrochemical operation by inductively coupled plasma optical emission spectrometry of aqueous 50 mm CsCl and MgCl2. We obtained a molar selectivity of Mg2+ over Cs+ of 31 (strong Mg preference) in the potential range between −396 mV and −220 mV versus Ag/AgCl. By adjusting the operational potential window from −219 mV to +26 mV versus Ag/AgCl, Cs+ was preferred over Mg2+ by 1.7 times (Cs preference).
Atmospheric deposition and exceedances of critical loads from 1800−2025 for the conterminous United States
Authors: Clark Christopher M. , Phelan Jennifer , Doraiswamy Prakash , Buckley John , Cajka James C. , Dennis Robin L. , Lynch Jason , Nolte Christopher G. , Spero Tanya L. 
Published: May 2018

AbstractAtmospheric deposition of nitrogen (N) and sulfur (S) has increased dramatically over pre‐industrial levels, with many potential impacts on terrestrial and aquatic ecosystems. Quantitative thresholds, termed “critical loads” (CLs), have been developed to estimate the deposition rate above which damage is thought to occur. However, there remains no comprehensive comparison of when, where, and over what time periods individual CLs have been exceeded. We addressed this knowledge gap by combining several published data sources for historical and contemporary deposition, and overlaying these on six CL types from the National Critical Loads Database (NCLDv2.5; terrestrial acidification, aquatic acidification, lichen, nitrate leaching, plant community composition, and forest‐tree health) to examine exceedances from 1800 to 2011. We expressed CLs as the minimum, 10th, and 50th percentiles within 12‐km grid cells. Minimum CLs were relatively uniform across the country (200–400 eq·ha−1·yr−1), and have been exceeded for decades beginning in the early 20th century. The area exceeding minimum CLs peaked in the 1970s and 1980s, exposing 300,000 to 3 million km2 (depending on the CL type) to harmful levels of deposition, with a total area exceeded of 5.8 million km2 (~70% of the conterminous United States). Since then, deposition levels have dropped, especially for S, with modest reductions in exceedance by 2011 for all CL types, totaling 5.2 million km2 in exceedance. The 10th and 50th percentile CLs followed similar trends, but were not consistently available at the 12‐km grid scale. We also examined near‐term future deposition and exceedances in 2025 under current air quality regulations, and under various scenarios of climate change and additional nitrogen management controls. Current regulations were projected to reduce exceedances of any CL from 5.2 million km2 in 2011 to 4.8 million km2 in 2025. None of the additional N management or climate scenarios significantly affected areal exceedances, although exceedance severity declined. In total, it is clear that many CLs have been exceeded for decades, and are likely to remain so in the short term under current policies. Additionally, we suggest many areas for improvement to enhance our understanding of deposition and its effects to support informed decision making.
The duality of ocean acidification as a resource and a stressor
Authors: Connell Sean D. , Doubleday Zoë A. , Foster Nicole R. , Hamlyn Sarah B. , Harley Christopher D. G. , Helmuth Brian , Kelaher Brendan P. , Nagelkerken Ivan , Rodgers Kirsten L. , Sarà Gianluca , Russell Bayden D. 
Published: May 2018

AbstractEcologically dominant species often define ecosystem states, but as human disturbances intensify, their subordinate counterparts increasingly displace them. We consider the duality of disturbance by examining how environmental drivers can simultaneously act as a stressor to dominant species and as a resource to subordinates. Using a model ecosystem, we demonstrate that CO2‐driven interactions between species can account for such reversals in dominance; i.e., the displacement of dominants (kelp forests) by subordinates (turf algae). We established that CO2 enrichment had a direct positive effect on productivity of turfs, but a negligible effect on kelp. CO2 enrichment further suppressed the abundance and feeding rate of the primary grazer of turfs (sea urchins), but had an opposite effect on the minor grazer (gastropods). Thus, boosted production of subordinate producers, exacerbated by a net reduction in its consumption by primary grazers, accounts for community change (i.e., turf displacing kelp). Ecosystem collapse, therefore, is more likely when resource enrichment alters competitive dominance of producers, and consumers fail to compensate. By recognizing such duality in the responses of interacting species to disturbance, which may stabilize or exacerbate change, we can begin to understand how intensifying human disturbances determine whether or not ecosystems undergo phase shifts.
An assessment of assumptions and uncertainty in deuterium‐based estimates of terrestrial subsidies to aquatic consumers
Authors: Brett Michael T. , Holtgrieve Gordon W. , Schindler Daniel E. 
Published: May 2018

AbstractThe deuterium ratio (2H/1H) in tissue is often used to estimate terrestrial subsidies to aquatic consumers because of strongly differentiated values between terrestrial and aquatic primary producers. However, quantitative deuterium‐based analyses of terrestrial resource assimilation are highly dependent on several poorly defined assumptions. We explored the sensitivity of these estimates to assumptions regarding environmental water contributions to consumer deuterium content (ω) and algal photosynthetic hydrogen discrimination (εH). We also tested whether 13C/12C and 2H/1H‐based estimates of terrestrial resource assimilation give similar outcomes. The average of the 12 experiments that have directly estimated proportional contributions of environmental water to consumer tissue 2H/1H was 0.27 ± 0.11 (mean ± SD), with similar values for invertebrates and fish. Conversely, of the 28 field studies that have used 2H/1H to characterize aquatic food webs, all but one assume a value that is less than our current best estimate, usually substantially less. A reanalysis of the raw data from four recent case studies indicates the calculated terrestrial contribution to aquatic consumers is extremely sensitive to this assumption. When the authors’ original assumptions were used (i.e., ω = 0.16 ± 0.05), the estimated proportional contribution of terrestrial resources to aquatic consumers (θT) averaged 29 ± 17%, and when ω = 0.27 was used the average estimated assimilation of allochthonous resources was ≈0.00. A compilation of published photosynthetic hydrogen discrimination values for microalgae averaged εH = −150 ± 27‰ (SD, n = 99), and a sensitivity analysis showed the outcomes of these calculations were also strongly influenced by uncertainty in εH. There was no statistical association between 13C/12C and 2H/1H‐based estimates of terrestrial subsidies (r = −0.12, n = 274). This analysis indicates that the assumptions in deuterium‐based estimates of terrestrial resource assimilation are highly influential but poorly constrained; therefore, the impact of these assumptions on calculated outputs must be carefully assessed and thoroughly reported. Due to the highly uncertain assumptions inherent in deuterium‐based analyses, we urge much more caution when using this approach to estimate terrestrial subsidies to consumers in aquatic ecosystems.
A microfluidic glucose sensor incorporating a novel thread‐based electrode system
Authors: Gaines Michelle , Gonzalez‐Guerrero Maria Jose , Uchida Kathryn , Gomez Frank A. 
Published: May 2018

AbstractAn electrochemical sensor for the detection of glucose using thread‐based electrodes and fabric is described. This device is relatively simple to fabricate and can be used for multiple readings after washing with ethanol. The fabrication of the chip consisted of two steps. First, three thread‐based electrodes (reference, working, and counter) were fabricated by painting pieces of nylon thread with either layered silver ink and carbon ink or silver/silver chloride ink. The threads were then woven into a fabric chip with a beeswax barrier molded around the edges in order to prevent leaks from the tested solutions. A thread‐based working electrode consisting of one layer of silver underneath two layers of carbon was selected to fabricate the final sensor system. Using the chip, a PBS solution containing glucose oxidase (GOx) (10 mg/mL), potassium ferricyanide (K3[Fe(CN)6]) (10 mg/mL) as mediator, and different concentrations of glucose (0‐25 mM), was measured by cyclic voltammetry (CV). It was found that the current output from the oxidation of glucose was proportional to the glucose concentrations. This thread‐based electrode system is a viable sensor platform for detecting glucose in the physiological range.
A plastic holographic waveguide combiner for light‐weight and highly‐transparent augmented reality glasses
Authors: Yoshida Takuji , Tokuyama Kazutatsu , Takai Yuichi , Tsukuda Daisuke , Kaneko Tsuyoshi , Suzuki Nobuhiro , Anzai Takafumi , Yoshikaie Akira , Akutsu Katsuyuki , Machida Akio 
Published: May 2018

AbstractThere is a high demand for light‐weight, stylishly designed augmented reality (AR) glasses with natural see‐through capabilities for the wide‐spread distribution of novel wearable device to general consumers. We have successfully developed a unique production process of a holographic waveguide combiner that enables us to laminate holographic optical elements (HOEs) onto a plastic substrate with optical grade quality. The plastic substrate waveguide combiner has a number of advantages over conventional glass substrate combiners; the plastic substrate makes AR glasses lighter in weight and unbreakable. With the lamination process of HOEs, we can apply them to a various designs to satisfy general customers' wide range of preferences for the style. We also potentially made it possible for the holographic waveguide combiner to be produced in larger volumes at lower costs by using our novel roll‐to‐roll hologram recording and laminating process. In this paper, we present our approach of the plastic substrate HOE production process for AR glasses.
Predicting positive outcomes for waterfowl hunters and waterfront residents
Authors: Triezenberg Heather A. , Knuth Barbara A. 
Published: May 2018

ABSTRACTSocial conflicts among wildlife stakeholders can suggest possible new directions for wildlife management, including opportunities to expand the base of stakeholders supporting active management. In response to New York State Department of Environmental Conservation information needs, we examined potential conflicts between waterfowl hunters and waterfront residents to understand their attitudes toward hunting along developed waterfronts and how spatial proximity was related to likelihood of waterfowl hunters’ experiences of harassment by waterfront residents. We sent mail‐back questionnaires to waterfowl hunters (n = 1,000) and waterfront residents (n = 1,000) near Lake Ontario in the greater‐Rochester area of New York, USA. We identified factors predicting acceptance of waterfowl hunting along developed waterfronts. Waterfront residents who knew waterfowl hunters were more supportive of waterfowl hunting than residents who did not know hunters. Hunters who hunted closer to occupied dwellings (e.g., waterfront homes) were more likely to experience harassment from residents than hunters who hunted farther away. Educational communication and policies that address public access, safety, safe distance of hunting from homes, and rules and regulations relating to waterfowl hunting are needed for acceptance of waterfowl hunting along developed waterfronts. Non‐hunters who accept hunting activities have the potential to positively affect wildlife management by expanding the base of involved, supportive stakeholders. © 2018 The Wildlife Society.
Nutritional carrying capacity for cervids following disturbance in hardwood forests
Authors: Nanney Jordan S. , Harper Craig A. , Buehler David A. , Bates Gary E. 
Published: May 2018

ABSTRACTClosed‐canopy forests dominate the landscape across much of the eastern United States and often lack a well‐developed understory, which limits nutrition available for cervids. We evaluated the influence of timber harvest combined with prescribed fire, herbicide treatment, or fire and herbicide treatment in young mixed‐hardwood forests on forage availability and nutritional carrying capacity (NCC) for elk (Cervus canadensis) and white‐tailed deer (Odocoileus virginianus) in the Cumberland Mountains, Tennessee, USA, July–August 2013–2015. We compared forage availability, NCC using a 12% and 14% crude protein nutritional constraint, and vegetation composition in untreated mature forest stands, reclaimed surface mines, and 6 timber harvest treatments (timber harvest only, with early growing‐season fire, with late growing‐season fire, with herbicide only, with herbicide and early growing‐season fire, and with herbicide and late growing‐season fire). Forage availability in treatments involving timber harvest was greater than in untreated mature forest stands and reclaimed surface mines. Forage availability estimates in treatments involving herbicide and prescribed fire were less than all other timber harvest treatments. Nutritional carrying capacity estimates at the 12% and 14% crude protein constraints were greater in timber harvest treatments and on reclaimed surface mines than in untreated mature forest stands. Herbaceous species coverage was greater and woody species coverage was less on reclaimed surface mines and in timber harvest treatments involving herbicide and prescribed fire than in all other timber harvest treatments and untreated mature forest stands. Greater coverage of herbaceous forage species in treatments involving herbicide and prescribed fire and on reclaimed surface mines compensated for reduced forage availability and resulted in NCC estimates similar to all other timber harvest treatments. Our data indicate using periodic prescribed fire and following an herbicide application with prescribed fire are effective techniques to transition young mixed‐hardwood forest communities to early successional communities and maintain increased forage availability and NCC for elk and deer. © 2018 The Wildlife Society.