bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solvatochromism, Reversible Chromism and Self‐Assembly Effects of Heteroatom‐Assisted Aggregation‐Induced Enhanced Emission (AIEE) Compounds
Authors: Niu Caixia , You Ying , Zhao Liu , He Dacheng , Na Na , Ouyang Jin 
Published: August 2015

AbstractTwo compounds, 9,10‐bis[2‐(quinolyl)vinyl]anthracene (BQVA) and 9,10‐bis[2‐(naphthalen‐2‐yl)vinyl]anthracene (BNVA), have been synthesised and investigated. Both of them have aggregation‐induced enhanced emission (AIEE) properties. Heteroatom‐assisted BQVA shows solvatochromism, reversible chromism properties and self‐assembly effects. When increasing the solvent polarities, the green solution of BQVA turns to orange with a redshift of the fluorescence emission wavelengths from λ=527 to 565 nm. Notably, BQVA exhibits reversible chromism properties, including mechano‐ and thermochromism. The as‐prepared BQVA powders show green fluorescence (λem=525 nm) and the colour can turn into orange (λem=573 nm) after grinding. Interestingly, the orange colour can return at high temperature. Based on these reversible chromism properties, a simple and convenient erasable board has been designed. Different from BQVA, non‐heteroatom‐assisted BNVA has no clear chromic processes. The results obtained from XRD, differential scanning calorimetry, single‐crystal analysis and theoretical calculations indicate that the chromic processes depend on the heteroatoms in BQVA. Additionally, BQVA also exhibits excellent self‐assembly effects in different solvents. Homogeneous nanospheres are formed in mixtures of tetrahydrofuran and water, which are then doped into silica nanoparticles and treated with 3‐aminopropyltriethoxysilane to give amino‐functionalised nanoparticles (BQVAAFNPs). The BQVAAFNPs could be used to stain protein markers in polyacrylamide gel electrophoresis.
The Solid Solution Sr1−xBaxGa2: Substitutional Disorder and Chemical Bonding Visited by NMR Spectroscopy and Quantum Mechanical Calculations
Authors: Pecher Oliver , Mausolf Bernhard , Lamberts Kevin , Oligschläger Dirk , Niewieszol (née Merkens) Carina , Englert Ulli , Haarmann Frank 
Published: August 2015

AbstractComplete miscibility of the intermetallic phases (IPs) SrGa2 and BaGa2 forming the solid solution Sr1−xBaxGa2 is shown by means of X‐ray diffraction, thermoanalytical and metallographic studies. Regarding the distances of Sr/Ba sites versus substitution degree, a model of isolated substitution centres (ISC) for up to 10 % cation substitution is explored to study the influence on the Ga bonding situation. A combined application of NMR spectroscopy and quantum mechanical (QM) calculations proves the electric field gradient (EFG) to be a sensitive measure of different bonding situations. The experimental resolution is boosted by orientation‐dependent NMR on magnetically aligned powder samples, revealing in first approximation two different Ga species in the ISC regimes. EFG calculations using superlattice structures within periodic boundary conditions are in fair agreement with the NMR spectroscopy data and are discussed in detail regarding their application on disordered IPs.
A Combined Experimental and Theoretical Study on the Stereodynamics of Monoaza[5]helicenes: Solvent‐Induced Increase of the Enantiomerization Barrier in 1‐Aza‐[5]helicene
Authors: Caronna Tullio , Mele Andrea , Famulari Antonino , Mendola Daniele , Fontana Francesca , Juza Markus , Kamuf Matthias , Zawatzky Kerstin , Trapp Oliver 
Published: August 2015

AbstractHelicenes and heterohelicenes are attractive compounds with great potential in materials sciences to be used in optoelectronics as ligand backbones in enantioselective catalysis and as chiral sensors. The properties of these materials are related to the stereodynamics of these helical chiral compounds. However, little is known about features controlling stereodynamics in helicenes; in particular, for heterohelicenes the position of the heteroatom could be relevant in this respect. Herein the complete stereodynamic characterization of monoaza[5]helicenes is shown by enantioselective dynamic HPLC and DFT calculations. At variance with previous theoretical calculations, 1‐aza[5]helicene shows a surprisingly high enantiomerization barrier, which is triggered by specific solvent interactions.
Elastic component‐based applications in PaaS clouds
Authors: Pokahr Alexander , Braubach Lars 
Published: August 2015

SummaryElasticity is the capability of an application to adapt its resource usage to the current workload of the system. Existing platform‐as‐a‐service (PaaS) solutions concentrate on web applications and do not support elasticity for other kinds of applications. To change this, in this paper, the vision and partial implementation for a component‐based PaaS cloud is proposed consisting of a programming model and an autonomic manager for safeguarding non‐functional application requirements. To illustrate this vision, the paper focuses on two key features of a PaaS infrastructure, the scale‐out of services and the on‐demand deployment of application resources. The former allows for increasing the performance by distributing service calls among several service providers working in parallel, and the latter refers to the automatic packaging and transfer of needed deployment units. It will be shown how these aspects have been solved within the Jadex PaaS cloud infrastructure. Both concepts have been validated using an application scenario, which highlights the advantages of automatic service scaling and deployment for developers and users. Copyright © 2015 John Wiley & Sons, Ltd.
A generic API for load balancing in distributed systems for big data management
Authors: Antoine Maeva , Pellegrino Laurent , Huet Fabrice , Baude Françoise 
Published: August 2015

SummaryDistributed systems for big data management very often face the problem of load imbalance among nodes. To address this issue, there exist almost as many load balancing strategies as there are different systems. When designing a scalable distributed system geared towards handling large amounts of information, it is often not so easy to anticipate which kind of strategy will be the most efficient to maintain adequate performance regarding response time, scalability, and reliability at any time. Based on this observation, we describe a generic API to implement and experiment any strategy independently from the rest of the code, prior to a definitive choice for instance. We then show how existing load balancing strategies used by famous systems could be implemented with this API. We also present how this work has helped us implement load balancing on our distributed system and modify the behavior of our strategy in a few lines of code. This led us to easily perform various experiments to determine the most efficient scheme for our system. This paper is an extension to our work presented at Workshop on Parallel and Distributed Computing for Big Data Applications (WPBA) 2014. We detail here more experiments and extend the use of the API to a broad class of big data storage systems. Copyright © 2015 John Wiley & Sons, Ltd.
Effect of Erbium on the Photocatalytic Activity of TiO2/Ag Nanocomposites under Visible Light Irradiation
Authors: Prakash Natarajan , Karthikeyan Rajan , Thangaraju Dheivasigamani , Navaneethan Mani , Arivanandhan Mukannan , Koyama Tadanobu , Hayakawa Yasuhiro 
Published: August 2015

AbstractErbium co‐doped TiO2/Ag catalysts are synthesized by using a simple, one‐step solvothermal method and characterized by X‐ray diffraction, field‐emission scanning electron microscopy, transmission electron microscopy, Raman analysis, X‐ray photoelectron spectroscopy, and diffuse reflectance spectroscopy. The catalysts exhibit anatase crystal structures with increased visible light absorption compared with pure TiO2. Enhanced photocatalytic activity is observed with Er co‐doped TiO2/Ag nanocomposites for Rhodamine B degradation under visible light irradiation. The photocatalytic activity of 1 % Er co‐doped TiO2/Ag is much higher than that of TiO2/Ag, TiO2/Er, pure TiO2, and commercial Degussa P25. The kinetics of the degradation process are studied and the pseudo‐first‐order rate constant (k) and half‐life time (t1/2) of the reaction are calculated. The enhanced activity might be accredited to the efficient separation of electron–hole pairs by silver and higher visible light absorption of TiO2 induced by Er.
Ag on Pt(111): Changes in Electronic and CO Adsorption Properties upon PtAg/Pt(111) Monolayer Surface Alloy Formation
Authors: Diemant Thomas , Schüttler Konstantin M. , Behm R. Jürgen 
Published: August 2015

AbstractThe electronic and chemical (adsorption) properties of bimetallic Ag/Pt(111) surfaces and their modification upon surface alloy formation, that is, during intermixing of Ag and Pt atoms in the top atomic layer upon annealing, were studied by X‐ray photoelectron spectroscopy (XPS) and, using CO as probe molecule, by temperature‐programmed desorption (TPD) and infrared reflection absorption spectroscopy (IRRAS), respectively. The surface alloys are prepared by deposition of sub‐monolayer Ag amounts on a Pt(111) surface at room temperature, leading to extended Ag monolayer islands on the substrate, and subsequent annealing of these surfaces. Surface alloy formation starts at ≈600–650 K, which is evidenced by core‐level shifts (CLSs) of the Ag(3d5/2) signal. A distinct change of the CO adsorption properties is observed when going to the intermixed PtAg surface alloys. Most prominently, we find the growth of a new desorption feature at higher temperature (≈550 K) in the TPD spectra upon surface alloy formation. This goes along with a shift of the COad‐related IR bands to lower wave number. Surface alloy formation is almost completed after heating to 700 K.
Probabilistic routing algorithm based on contact duration and message redundancy in delay tolerant network
Authors: Yu Chen , Tu Zhongqiu , Yao Dezhong , Lu Feng , Jin Hai 
Published: August 2015

SummaryThe Delay Tolerant Network (DTN) is a novel Wireless Sensor Network architecture for an opportunistic network environment, in which environment end‐to‐end connection cannot be set up constantly between source and destination nodes pairs. In this paper, we have proposed a novel routing algorithm based on a hybrid of message delivery probability and message redundancy to reduce the communication overhead while keeping the high message delivery ratio. In this algorithm, the message delivery probability is calculated by the combined impact of meeting frequency and length of contact duration. Further, the maximum number of copies of the message is designated in the source node, and the forwarding task of message copies is assigned to relay nodes based on the pattern of a binary tree, so that multi‐path parallel transmission can be implemented on message forwarding. Simulated results showed that the proposed routing algorithm can achieve a higher efficiency of message delivery than the related existing routing algorithms and it can also reduce the communication overhead significantly in general DTNs. Copyright © 2015 John Wiley & Sons, Ltd.
Performance evaluation of HDAF relaying systems for pilot and data symbol burst transmission over quasi‐static Rayleigh fading channels
Authors: Lim Sungmook , Ko Kyunbyoung 
Published: August 2015

SummaryThis paper analyzes averaged symbol error probabilities of burst transmission consisting of pilot and data symbols for hybrid adaptive decode‐or‐amplify‐forward (HDAF) relaying systems. Under the assumption of quasi‐static Rayleigh fading channels with independent and non‐identically distribution, we consider a channel estimation scheme based on pilot symbols and show how channel estimation error affects received signal‐to‐noise ratio (SNR) and symbol error probability (SEP). Firstly, all the possible detection error‐events are presented for all the relay nodes, and their probabilities are derived as forms related with data symbol burst transmission. For the given error event, we analyze the conditional SEP as an exact form and then, the averaged SEP (ASEP) is approximately derived as a closed‐form. The simulation results verify that our derived ASEP expression is accurate over all the regions of SNR. Utilizing the proposed expressions, we can evaluate ASEP performance of HDAF relay systems easily and fast. Copyright © 2015 John Wiley & Sons, Ltd.
System analysis of Neo‐Gothic vaults / Systemanalyse neugotischer Gewölbe
Authors: Piehler Jens , Hanse Michael , Kapphahn Gerd 
Published: August 2015

AbstractFrom the middle of the 19th century until the beginning of World War I, many buildings were built in the Neo‐Gothic style. In this period, Gothic elements were built regarding the former needs to save material. These lightweight and thin vaults are often relatively fragile support systems. They tend to show systemic damages in the form of significant crack patterns in the vault caps and arches. In the research project Preservation of Neo‐Gothic vault structures, typical damages of Neo‐Gothic vaulted structures are analyzed with the objective to find sustainable and rehabilitative measures. In this context, since 2011, numerical and experimental studies have been carried out on a reference structure. Measured values of a 3D laser scanning, including all the imperfections of the structure, provide the basis of the geometry model, created for the finite element simulation. The system behavior was studied experimentally in the non‐critical load range with a load test for the calibration of this numerical model. In this paper, the project framework as well as the implementation and the evaluation of the load test are presented. In further papers, the transfer of the geodetic measurement data to the numerical model and the consideration of the load test results within a realistically finite element simulation will be addressed.
Induced responses to grazing by an insect herbivore (Acentria ephemerella) in an immature macrophyte (Myriophyllum spicatum): an isotopic study
Authors: Rothhaupt Karl‐Otto , Fornoff Felix , Yohannes Elizabeth 
Published: August 2015

AbstractWhile the mechanisms by which adult terrestrial plants deploy constitutive and induced responses to grazing pressure are well known, the means by which young aquatic plants defend themselves from herbivory are little studied. This study addresses nitrogen transport in the aquatic angiosperm Myriophyllum spicatum in response to herbivore exposure. Nitrogen tracers were used to monitor nitrogen uptake and reallocation in young plants in response to grazing by the generalist insect herbivore Acentria ephemerella. Total nitrogen content (N%) and patterns of nitrogen uptake and allocation (δ15N) were assessed in various plant tissues after 24 and 48 h. Following 24 h exposure to herbivore damage (Experiment 1), nitrogen content of plant apices was significantly elevated. This rapid early reaction may be an adaptation allowing the grazer to be sated as fast as possible, or indicate the accumulation of nitrogenous defense chemicals. After 48 h (Experiment 2), plants' tips showed depletion in nitrogen levels of ca. 60‰ in stem sections vulnerable to grazing. In addition, nitrogen uptake by grazed and grazing‐prone upper plant parts was reduced and nutrient allocation into the relatively secure lower parts increased. The results point to three conclusions: (1) exposure to an insect herbivore induces a similar response in immature M. spicatum as previously observed in mature terrestrial species, namely a rapid (within 48 h) reduction in the nutritional value (N%) of vulnerable tissues, (2) high grazing intensity (100% of growing tips affected) did not limit the ability of young plants to induce resistance; and (3) young plants exposed to herbivory exhibit different patterns of nutrient allocation in vulnerable and secure tissues. These results provide evidence of induced defense and resource reallocation in immature aquatic macrophytes which is in line with the responses shown for mature aquatic macrophytes and terrestrial plants.
Multifunctional Hybrid Silica Nanoparticles with a Fluorescent Core and Active Targeting Shell for Fluorescence Imaging Biodiagnostic Applications
Authors: Santiago Ana M. , Ribeiro Tânia , Rodrigues Ana S. , Ribeiro Bruno , Frade Raquel F. M. , Baleizão Carlos , Farinha José Paulo S. 
Published: August 2015

AbstractWe prepared hybrid nanoparticles with a brightly fluorescent silica core and a biocompatible thermoresponsive polymer shell containing tumor‐targeting folic acid (FA) groups. The silica core has a perylenediimide fluorescent dye anchored covalently to the structure for traceability and bioimaging applications. The polymeric shell was synthesized by reversible addition–fragmentation chain‐transfer (RAFT) polymerization to guarantee the homogeneous size of the particle shell. The shell is composed of copolymer chains with one block of oligo(ethylene glycol)methacrylate and 2‐(2′‐methoxyethoxy)ethylmethacrylate with another block of the reactive monomer N‐acryloxysuccinimide (NAS). The NAS groups were used to covalently attach a large amount of amino‐functionalized FA to the particle shells to provide active targeting properties towards cancer cells and tissues. The targeting capability of the folate‐containing nanoparticles was evaluated against NCI‐H460 tumor cells, which overexpress folate receptors. The nanoparticles with FA show a higher uptake efficiency compared to that of the equivalent nanoparticles without FA. This result validates the imaging capabilities and active targeting efficiency of our nanoparticles, an important step towards the goal of developing vehicles for precision drug delivery systems that combine therapeutic and diagnostic (theranostic) functionalities with large drug payloads, active targeting, and stimuli‐activated drug release.
Methylmercury biomagnification in an Arctic pelagic food web
Authors: Ruus Anders , Øverjordet Ida B. , Braaten Hans Fredrik V. , Evenset Anita , Christensen Guttorm , Heimstad Eldbjørg S. , Gabrielsen Geir W. , Borgå Katrine 
Published: August 2015

Abstract

Mercury (Hg) is a toxic element that enters the biosphere from natural and anthropogenic sources, and emitted gaseous Hg enters the Arctic from lower latitudes by long-range transport. In aquatic systems, anoxic conditions favor the bacterial transformation of inorganic Hg to methylmercury (MeHg), which has a greater potential for bioaccumulation than inorganic Hg and is the most toxic form of Hg. The main objective of the present study was to quantify the biomagnification of MeHg in a marine pelagic food web, comprising species of zooplankton, fish, and seabirds, from the Kongsfjorden system (Svalbard, Norway), by use of trophic magnification factors. As expected, tissue concentrations of MeHg increased with increasing trophic level in the food web, though at greater rates than observed in several earlier studies, especially at lower latitudes. There was strong correlation between MeHg and total Hg concentrations through the food web as a whole. The concentration of MeHg in kittiwake decreased from May to October, contributing to seasonal differences in trophic magnification factors. The ecology and physiology of the species comprising the food web in question may have a large influence on the magnitude of the biomagnification. A significant linear relationship was also observed between concentrations of selenium and total Hg in birds but not in zooplankton, suggesting the importance of selenium in Hg detoxification for individuals with high Hg concentrations. Environ Toxicol Chem 2015;34:2636–2643. © 2015 SETAC
Metabolomics confirms that dissolved organic carbon mitigates copper toxicity
Authors: Taylor Nadine S. , Kirwan Jennifer A. , Yan Norman D. , Viant Mark R. , Gunn John M. , McGeer James C. 
Published: August 2015

Abstract

Reductions in atmospheric emissions from the metal smelters in Sudbury, Canada, produced major improvements in acid and metal contamination of local lakes and indirectly increased dissolved organic carbon (DOC) concentrations. Metal toxicity, however, has remained a persistent problem for aquatic biota. Integrating high-throughput, nontargeted mass spectrometry metabolomics with conventional toxicological measures elucidated the mediating effects of dissolved organic matter (DOM) on the toxicity of Cu to Daphnia pulex-pulicaria, a hybrid isolated from these soft water lakes. Two generations of daphniids were exposed to Cu (0–20 μg/L) at increasing levels of natural DOM (0–4 mg DOC/L). Added DOM reduced Cu toxicity monotonically with median lethal concentration values increasing from 2.3 μg/L Cu without DOM to 22.7 μg/L Cu at 4 mg DOC/L. Reproductive output similarly benefited, increasing with DOM, yet falling with increases in Cu. Second generation reproduction was more impaired than the first generation. Dissolved organic matter had a greater influence than Cu on the metabolic status of the daphniids. Putative identification of metabolite peaks indicated that DOM elevation increased the metabolic energy status of the first generation animals, but this benefit was reduced in the second generation, although evidence of increased oxidative stress was detected. These results indicate that Sudbury's terrestrial ecosystems should be managed to increase aquatic DOM supply to enable daphniid colonists to both survive and foster stable populations. Environ Toxicol Chem 2016;35:635–644. © 2015 SETAC
Technology options for reducing CO2 in China's electricity sector in 2010–2030: From the perspective of internal and social costs
Authors: Wen Zongguo , Zhang Xuan , Yu Xuewei , Di Jinghan 
Published: August 2015

Abstract:This paper creates a technology roadmap for China's electricity sector on CO2 mitigation based on cost‐effective analysis (CEA) and cost‐benefit analysis (CBA). We use mitigation targets for 2020 and 2030 to determine the required implementation degrees of 13 selected power‐generating technologies. According to the initial investment, operational costs, and external costs of major pollutants, we assigned a priority rank to each technology, which is derived on the basis of internal costs and social costs. A comparison of present value costs of major generating technologies shows that hydroelectricity bears the highest total cost, while cogeneration of heat and power bears the lowest cost. The technology with the highest total social benefit is also hydroelectricity, while carbon capture and sequestration (CCS) yields the lowest social benefit. By 2030, 6 of the 13 technologies can realize net internal benefits and all 13 technologies except CCS can realize net social benefits. The top three technologies based on internal levelized cost are: cogeneration of heat and power, biomass power generation, and wind power generation. Based on social levelized cost, the highest priority technologies are: integrated gasification combined cycle, biomass power generation, and wind power generation. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd