Miracle-dz/UniFAR-FTUs huggingface dataset:
Unsupported Cu-Pt Core-Shell Nanoparticles: Oxygen Reduction Reaction (ORR) Catalyst with Better Activity and Reduced Precious Metal Content

An unsupported Cu-Pt core-shell catalyst is prepared by a transmetalation reaction between copper and Pt 2+ ions, and a Cu-Pt bimetallic alloy catalyst by a simultaneous reduction reaction. Both catalysts are subjected to electrochemical leaching without further treatment and their electrochemical characteristics and ORR activities are compared to that of a standard Pt black catalyst. Potential cycling in 0.1 M HClO 4 and 0.5 M H 2 SO 4 shows that the core-shell catalyst is highly stable and the electrochemical features show that it is purely Pt on the catalyst surface. The electrochemical surface area of the Cu-Pt core-shell catalyst is much higher than that of the Pt black. When the Pt loading on the electrode is increased with Pt black catalyst to match its geometric electrochemical surface area (cm 2 /electrode area (cm 2 )) with that of Cu-Pt core-shell catalyst, the activity of the latter is still higher. The mass activities of Pt black, Cu-Pt binary alloy, and Cu-Pt core-shell catalysts measured using a rotating disk electrode are 0.053, 0.153 and 0.262 A mg ―1 Pt , and their respective specific activities are 197, 496, and710 μA cm ―2 Pt .
Spinodal Decomposition under Layer by Layer Growth Condition and High Curie Temperature Quasi-One-Dimensional Nano-Structure in Dilute Magnetic Semiconductors

We show that spinodal decomposition under layer by layer crystal growth condition leads to characteristic quasi-one-dimensional nano-structures in dilute magnetic semiconductors (DMS). It is found that the DMS systems can form rather large clusters with highly anisotropic shape even for low concentrations. It is suggested that the blocking phenomena in the super-paramagnetism, the magnetic dipole–dipole interaction and the network of the one-dimensional structures should be considered to understand the magnetism in DMS. Based on the present simulations, we propose that the delta-doping method can be effective approach to realize high Curie temperature.
Localization Of Sensors In Presence Of Fading And Mobility

The objective of this dissertation is to estimate the location of a sensor through analysis of signal strengths of messages received from a collection of mobile anchors. In particular, a sensor node determines its location from distance measurements to mobile anchors of known locations. We take into account the uncertainty and fluctuation of the received signal strength (RSS) as a result of fading and take into account the decay of the RSS which is proportional to the transmitter-receiver distance power raised to the path loss exponent (PLE). The objective is to characterize the channel in order to derive accurate distance estimates from RSS measurements and then utilize the distance estimates in locating the sensors. To characterize the channel, two techniques are presented for the mobile anchors to periodically estimate the channel’s PLE and fading parameter. Both techniques estimate the PLE by solving an equation via successive approximations. The formula in the first is stated directly from maximum-likelihood estimation (MLE) analysis whereas in the second is derived from a probability analysis. Then two distance estimates are proposed, one based on a derived formula and the other based on the MLE analysis. Then a location technique is proposed where two anchors are sufficient to uniquely locate a sensor. That is, the sensor narrows down its possible locations to two when collects RSS measurements transmitted by a mobile anchor, then uniquely determines its location when given a distance to the second anchor. Analysis shows the PLE has no effect on the accuracy of the channel characterization, the normalized error in the distance estimation is invariant to the estimated distance, and accurate location estimates can be achieved from a moderate sample of RSS measurements.
Secondary Organic Aerosol Formation vs Primary Organic Aerosol Emission: In Situ Evidence for the Chemical Coupling between Monoterpene Acidic Photooxidation Products and New Particle Formation over Forests

In a Eucalyptus forest in Portugal were investigated (a) the formation of secondary organic aerosol formed through the condensation of low vapor pressure products of monoterpenes (α- and β-pinene) photooxidation and (b) the chemical structure of these products related to their ability to form new particles. Two isomers of pinonic acid (cis- and trans-2,2-dimethyl-3-acetylcyclobutylethanoic acid) and norpinonic acid (cis- and trans-2,2-dimethyl-3-acetylcyclobutylmethanoic acid), pinic acid (cis-2,2-dimethyl-3-carboxycyclobutylethanoic acid), pinonaldehyde (2,2-dimethyl-3-acetylcyclobutylethanal), and nopinone (6,6-dimethylbicyclo[3.1.1]heptan-2-one) were detected in all forest aerosol samples. By considering the diurnal concentration pattern of the acidic products and Aitken nuclei observed during the same periods, our results indicated that cis- and trans-pinonic, cis- and trans- norpinonic and pinic acids are photooxidation products of α-pinene chemically coupled with new particles formed. Lipids such as.
A joint experimental and theoretical study on the effect of manganese doping on the structural, electrochemical and physical properties of lithium iron phosphate

Mn doped LiFe1−xMnxPO4 (x = 0, 0.01, 0.03, 0.05, 0.07) cathode materials are synthesized by a carbothermal reduction method. The structure, morphology and electrochemical performance of the samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman, and charging–discharging tests. It is found that an appropriate amount of Mn doping did not affect the olivine structure and morphology of LiFePO4, but greatly improves its electrochemical performance. Especially, the LiFe0.97Mn0.03PO4 sample exhibits the best electrochemical performance, which shows the maximum discharge capacity of 148.2 mA h g−1 at 0.1 C and a capacity retention ratio of 98% after 60 cycles at various rates. Based on first-principles density functional theory (DFT), the lithium ion migration channels, energy band structures, densities of states, and charge density diffusion of LiFePO4 and LiFe15/16Mn1/16PO4 are calculated to further investigate the influence of Mn doping on the LiFePO4 lattice. The results prove that the higher lithium ion conduction and electronic conductivity of LiFe15/16Mn1/16PO4 are attributed to Mn doping.
JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDSCAPE MANAGEMENT 2010 18(3): 188–195 SOLAR RADIATION ENERGY PULSATIONS IN A PLANT LEAF

Solar radiation energy is used by vegetation, which predetermines the existence of biosphere. The plant uses 1– 2% of the absorbed radiant energy for photosynthesis. All the remaining share of the absorbed energy, accounting for 99– 98%, converts into thermal energy in the plant leaf. At the lowest wind under natural surrounding air conditions, plant leaves change their position with respect to the Sun. An oscillating plant leaf receives a variable amount of solar radiation energy, which causes changes in the balance of plant leaf energies and a changing emission of heat in the leaf. The analysis of solar radiation energy pulsations in the plant leaf shows that when the leaf is in the edge positions of angles 10, 20 and 30 with respect to the Sun, 1.5%; 6% and 13% less of radiation energy reach the leaf, respectively. During periodic motion, when the amplitude of leaf oscillation is no bigger than 10, the plant surface receives up to 1.6% less of solar radiation energy within a certain period of time, and when the amplitude of oscillation reaches 30 up to 14% less of solar radiation energy reach the leaf surface. The total amount of radiant energy received during pulsations of solar radiation energy is not dependent on the frequency of oscillation in the same interval of time. Temperature pulsations occur in the leaf due to solar radiation energy pulsations when the plant leaf naturally changes its position with respect to the Sun.
Subsoil water available in suction and poor in amount under continuous grassland use

Abstract Soil water storage in grassland is critical to regulate herbage yield while it may be threatened by continuous land use without plowing because of the progress of soil compaction associated with worsening soil hydraulic properties. This study aimed at contrasting the quantity and the availability of soil water in a meadow which had not been renovated for 13 years. We monitored matric potentials and mass soil water contents to 100 cm depth from autumn to winter in which plant transpiration was dormant. Soil water capacities were determined with soil water characteristics. The measurements were made in both a harvesting area in which agricultural vehicles had been operated, and a tree cover area which had experienced almost no vehicle loads. The soil layer in the tree cover area had a larger capacity for readily available moisture than that in the harvesting area. The matric potentials in the tree cover area varied in time between 0 and -1000 cm regardless of depth while those in the harvesting area were rather steady. These suggested better pore water continuity in the tree cover area. In the subsoil layers in both the harvesting and the tree cover areas, the soil water contents in terms of actually stored water did not reach as high a level as those expected from the soil moisture characteristics of the matric potential of -1000 cm. On the other hand, the measured matric potentials were consistently readily available for plants during the entire period of measurement. The apparent discrepancy between the matric potentials in readily available vs. actually stored water implied that the subsoil layers had become drier than observed during the study period, and that soil water hysteresis had prevented the full recovery of the water storage.
An Automated System for Micro-Batch Protein Crystallization and Screening

An automatic sample dispenser has been constructed to aid with protein crystallization trials. This dispenser contains a bank of Hamilton syringes driven by stepper motors under computer control which is used to set up small samples (2 μl or less) for batch crystallization. Software has been written to create a series of trials which form a two-dimensional array of crystallization conditions. A specially designed fluoropolymer multibore microtip allows the very small volumes to be mixed and dispensed with great accuracy.
High mass resolution with a new variable anharmonicity Penning trap

A modified Penning trap has been developed and shown to yield 100 times narrower axial resonance linewidths on electrons than that of a previous unmodified Penning trap. An extra pair of electrodes is inserted in the standard trap configuration, which effectively nulls the quartic term in the trapping potential. With existing signal‐to‐noise limitations, an axial frequency resolution of 0.02 ppm can be obtained. This device is particularly attractive to high‐resolution mass spectrometry.
On highly excited electronic states of the NO molecule reached by multiphoton spectroscopy

A recent multiphoton experiment by Wallace and Innes involves an energy level of the NO molecule that belongs to a very interesting sequence of rovibronic states in which an np Rydberg complex (C 2Π+D 2Σ+, v = 6) and a regular and inverted valence state (B 2Πr, v = 24 and L 2Πi, v = 5) are strongly mixed with each other. This multistate interaction, which is typical for highly excited molecular states reached in multiphoton spectroscopy, is discussed as an unique example of a nontrivial case of Rydbergization of valence states. Gallusser’s vibronic coupling calculation and new interpretations of local perturbations in three different isotopes are used to establish the absolute vibrational numbering and the deperturbed rovibronic and spin–orbit constants of the L 2Πi state which had been poorly known previously.
Preparation of crosslinked composite nanoparticles

Crosslinked composite nanoparticles were prepared by adding a trifunctional monomer (trimethyol propane trimethacrylate) or a difunctional monomer (divinyl benzene) as a crosslinker into the emulsion polymerization system of styrene in the presence of inorganic nanosilica. A coupling agent, 3-methacryloxypropyltrimethoxysilane (MPS), was added along with the monomer, crosslinker, and silica to improve the interfacial interaction between silica and polymer and thus to obtain high binding efficiency. The role of MPS was examined. The effects of crosslinkers on the kinetics of emulsion polymerization, monomer conversion, and yield were investigated. The morphology of the composite particles was observed by TEM. The particle size and size distribution of composite latex particles were measured by the dynamic light scattering method. The binding efficiency and swelling ratio were determined by reluxing the sample in xylene using a Soxhlet extraction apparatus. FTIR spectra and TGA verified the participation of crosslinker and silica.
Size Control to a Sub-Nanometer Scale in Platinum Catalysts on Graphene

Size controlled Pt catalysts supported by graphene nanosheets (GNS) are successfully prepared by changing the loading of Pt at 10–70 wt % using an impregnation method. It is found that Pt sub-nanoclusters (0.8 nm) with an extremely large surface area (170 m2 g–1) are formed on the GNS support in a 10 wt % Pt/GNS catalyst. An increase in loading of Pt leads to an increase in the particle sizes of Pt, which results in lower activities for electro-oxidation of adsorbed CO. A core level shift of Pt 4f in XPS indicates that Pt is chemically interacted with graphene. The modification of catalytic properties and the electronic structure is ascribed to the interface interaction between Pt and graphene via π–d hybridization.
Separation of the trivalent actinides from the lanthanides by extraction chromatography

The following conditions were selected for optimum separation of the trivalent lanthanides from the trivalent actinides at room temperature: 10- by 100-mm column of 70- to 80-mesh Tee-Six powder containing 0.45 M HDEHP-heptane as the stationary phase, 0.025 M DTPA in 1 M monochloroacetic acid adjusted to a pH of 3.0 with NH/sub 4/OH as eluant, and a flow rate of 10 to 12 drops per minute. (LK)
Effect of confinement by porous materials on chemical reaction kinetics

A methodology for including the effects of nonidealities, such as confinement in a porous solid or solvation, into the calculation of bimolecular reaction rate constants is presented. The method combines the transition-state theory formalism with the Reactive Monte Carlo simulation method. The approach is computationally efficient and accurate, within the approximations imposed by transition-state theory and the intermolecular potentials. Several applications of the method are presented for the decomposition reaction, 2HI→H2+I2, including effects due to confinement within carbon micropores and due to inert solvents. The method can be readily extended to other chemical reaction rate calculations in which the structure and the activation energy of the transition state is known a priori.
Diameter dependence of addition reactions to carbon nanotubes

We present resonant Raman measurements on carbon nanotubes functionalized with primary alkyl groups of different chain length. From the resonance profiles of the radial breathing mode (RBM) we assign the chiral indices of the tubes in order to study the selective reactivity of different tubes. We focus on diameter dependence showing inversely proportional behaviour to diameter for both metallic and semiconducting nanotubes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multielement detection limits and sample nebulization efficiencies of an improved ultrasonic nebulizer and a conventional pneumatic nebulizer in inductively coupled plasma-atomic emission spectrometry

Two important aspects of the analytical performance of a newly developed ultrasonic nebulizer and a specially designed pneumatic nebulizer have been compared for use in inductively coupled plasma--atomic emission spectroscopy (ICP-AES). The ultrasonic nebulizer, when combined with a conventional aerosol desolvation apparatus, provided an order of magnitude or more improvement in simultaneous multielement detection limits as compared to those obtained when the pneumatic nebulizer was used either with or without desolvation. Application of a novel method for direct measurement of the overall efficiency of nebulization to the two systems showed that an approximately tenfold greater rate of sample delivery to the plasma torch was primarily responsible for the superior detection limits afforded by the ultrasonic nebulizer. A unique feature of the ultrasonic nebulizer described is the protection against chemical attack which is achieved by completely enclosing the transducer in an acoustically coupled borosilicate glass cylinder. Direct sample introduction, convenient sample change, and rapid cleanout are other important characteristics of the system which make it an attractive alternate to pneumatic nebulizer systems.
Reliability of Calf Bioelectrical Impedance Spectroscopy and Magnetic-Resonance-Imaging-Acquired Skeletal Muscle Hydration Measures in Healthy People

Purpose. The purpose of this study was to investigate the test-retest reliability, relative variability, and agreement between calf bioelectrical impedance-spectroscopy (cBIS) acquired extracellular fluid (ECF), intracellular fluid (ICF), total water and the ratio of ECF : ICF, magnetic-resonance-imaging (MRI) acquired transverse relaxation times ( <path id="x1D447" d="M649 676l-22 -187l-33 -2q3 56 -12 94q-8 20 -31.5 26.5t-86.5 6.5h-74l-90 -491q-4 -23 -6 -36.5t1 -25t7 -16.5t18 -9t27 -5t41 -3l-6 -28h-286l4 28q68 5 84 18.5t28 76.5l94 491h-55q-74 0 -100.5 -6t-41.5 -23q-24 -29 -54 -98l-32 1q32 98 53 188h22q7 -18 15 -22 t37 -4h417q23 0 33.5 5t25.5 21h23z" /> ), and apparent diffusion coefficient (ADC) of calf muscles of the same segment in healthy individuals. Methods. Muscle hydration measures were collected in 32 healthy individuals on two occasions and analyzed by a single rater. On both occasions, MRI measures were collected from tibialis anterior (TA), medial (MG), and lateral gastrocnemius (LG) and soleus muscles following the cBIS data acquired using XiTRON Hydra 4200 BIS device. The intraclass correlation coefficients (ICC 2,1), coefficient of variation (CV), and agreement between MRI and cBIS data were also calculated. Results. ICC 2,1 values for cBIS, , and ADC ranged from 0.56 to 0.92, 0.96 to 0.99, and 0.05 to 0.56, respectively. Relative variability between measures (CV) ranged from 14.6 to 25.6% for the cBIS data and 4.2 to 10.0% for the MRI-acquired data. The ratio of ECF : ICF could significantly predict of TA and soleus muscles. Conclusion. MRI-acquired measures of had the highest test-retest reliability of muscle hydration with the least error and variation on repeated testing. Hence, of a muscle is the most reliable and stable outcome measure for evaluating individual muscle hydration.
Potentiometric anion selective sensors

In comparison with selective receptors (and sensors) for cationic species, work on the selective complexation and detection of anions is of more recent date. There are three important components for a sensor, a transducer element, a membrane material that separates the transducer element and the aqueous solution, and the receptor molecule that introduces the selectivity. This review deals with potentiometric transduction elements that convert membrane potentials into a signal. The structure and properties of membrane materials is discussed. The nature of the anion receptor ultimately determines the selectivity. Both coordination chemistry and hydrogen bonding have been used to design anion receptor molecules. The integration of all three elements by covalent linkage of all elements in durable sensorsystem concludes the review.
Root Nonstructural Carbohydrates and Their Relationship with Autotrophic Respiration of Loblolly Pine (Pinus taeda L.)

Separating soil respiration (Rs) into heterotrophic (RH) and autotrophic (RA) components often relies on root-severing techniques with the presumption that RA will approach zero as root nonstructural carbohydrate (NSC) supply diminishes. To test this assumption, we evaluated changes in carbon dioxide (CO2) flux rates and NSC concentrations after severing Pinus taeda L. roots using laboratory and field approaches. After an 86-day laboratory incubation, soluble, insoluble, and total NSCs decreased by 60, 29, and 43 percent, respectively. RS and RA declined asymptotically, reduced by 86 and 95 percent, respectively. Correlation coefficients between RA and soluble, insoluble, and total NSCs were 0.90, 0.69, and 0.93, respectively. In a field study, respiration stabilized after 40 days with mean rates in root-severed areas 21. ± 0.5 percent less than in undisturbed areas. This relationship between total NSCs and RS, and the steady decline in RS and RA over time, validates the use of field-installed root-severing cores to measure RH.
Drying Kinetics of Magnesium Hydroxide of Different Morphological Micro Nanostructures

Two kinds of Mg(OH)2 nanosheets were prepared using a precipitation conversion method, and Mg(OH)2 microparticles were synthesized by a direct precipitation method. Drying kinetics experiments of magnesium hydroxide of three morphological micro nanostructures were performed and their drying curves as well as drying rate curves were obtained at 80–140°C. The equilibrium moisture adsorption isotherms of magnesium hydroxide of three morphological micro nanostructures at 12°C were obtained. Results indicate that drying rate curves of magnesium hydroxide microparticles exhibit three stages: a setup period, a constant rate drying period, and a falling rate drying period. Drying rate curves of magnesium hydroxide nanosheets (nanosheets A and nanosheets B) show the same three stages with a small descending trend of constant rate drying period. It is also found that equilibrium moisture contents of Mg(OH)2 nanosheets are larger than those of Mg(OH)2 microparticles under the same drying conditions. The hydroscopicity of nanosheets A is the strongest and that of microparticles is the weakest.
Characteristics of the ZnO thin film transistor by atomic layer deposition at various temperatures

ZnO thin films were deposited by atomic layer deposition (ALD) at various temperatures and the resulting electrical and chemical properties were examined. The fraction of O–H bonds in ZnO films decreased from 0.39 to 0.24 with increasing processing temperatures. The O/Zn ratio decreased from 0.90 at 70 °C to 0.78 at 130 °C. The carrier concentration and resistivity changed sharply with decreasing temperature. The ZnO thin film transistors (TFTs) were fabricated at processing temperatures of 70 to 130 °C and the electrical properties of the TFT were as follows: the field-effect mobility ranged from 8.82 × 10−3 to 6.11 × 10−3 cm2 V−1 s−1, the on/off current ratio ranged from 1.28 × 106 to 2.43 × 106, the threshold voltage ranged from −12.5 to 14.7 V and the subthreshold swing ranged from 1.21 to 24.1 V/decade. The electrical characteristics of the ZnO TFT were enhanced as the processing temperature decreased.