Miracle-dz/UniFAR-FTUs huggingface dataset:
Cadmium(II) and zinc(II) complexes with rigid 1-(1H-imidazol-4-yl)-3-(4H-tetrazol-5-yl)benzene and varied carboxylate ligands

Six new coordination polymers [Cd2(HL)2(pbda)(H2O)2]·4H2O (1), [Cd2(HL)2(mbda)(H2O)2]·6H2O (2), [Cd(H2L)(mmbda)(H2O)] (3), [Cd2(H2L)2(btca) (H2O)2]·4H2O (4), [Zn2(H2L)2(btca)] (5) and [Zn6(H2L)6(btca)3] (6) were synthesized by reactions of cadmium(II)/zinc(II) salts with a rigid ligand 1-(1H-imidazol-4-yl)-3-(4H-tetrazol-5-yl)benzene (H2L) and different carboxylic acids of 1,4-benzenedicarboxylic acid (H2pbda), 1,3-benzenedicarboxylic acid (H2mbda), 5-methyl-1,3-benzenedicarboxylic acid (H2mmbda), 1,2,4,5-benzenetetracarboxylic acid (H4btca), respectively. The structures of the complexes were determined by single crystal X-ray diffraction analysis. Although complexes 1 and 2 possess the same two-dimensional (2D) network with (4·82)-fes topology built from Cd(II)–(HL)− moieties, different coordinated orientation of auxiliary carboxylates of pbda2− and mbda2− pillar the 2D layer into distinct frameworks. Complex 1 is an unusual binodal (3,4)-connected three-dimensional (3D) dmc net with Point (Schlafli) symbol of (4·82)(4·85) while 2 is a rare binodal (3,4)-connected 3D architecture with a (4·6·8)(4·62·83) fsc-3,4-C2/c topology. Complexes 3 and 4 have the same 2D networks with (4,4) topology, and H-bonding or π–π stacking interactions extending the 2D layers into 3D supramolecular frameworks, respectively. Complexes 5 and 6 present a pair of pseudopolymorphs, and 5 is an uninodal (4,4)-connected 3D net with Point (Schlafli) symbol of (62·84)(64·82)2 while 6 is an unprecedented penta-nodal 4-connected net with (4·62·83)2(4·64·8)2(62·84)(64·82)4 topology. The thermal stability and photoluminescent property of the complexes were investigated.
On the temperature gradient in gases at various pressures

A careful re-examination of the problem of the temperature gradients through gases at various pressures has been attempted. Sets of curves indicating these gradients at various pressures and other interesting relations were obtained. Amongst other features, they show quite definitely the existence in contact with the vessel walls - at low pressures - of very large "temperature jumps. " An attempt to explain the general character of the results is based on the assumption of the presence at the walls, of a gas film possessing certain properties due to the attracting forces existing amongst wall molecules and gas molecules. Instead of using one thermocouple only to determine the temperature at any point in the enclosure, several thermocouples of differing thicknesses - and therefore differing curvature - were employed under identical conditions. Systematic differences amongst corresponding readings of the thermocouples were noticed. These may also be attributed to the presence round the various thermocouples of gas films whose thickness and character vary with the thickness of the couple.
Recognition of Largest Common Structural Fragment among a Variety of Chemical Structures

A computer program, called MAXFIT, has been developed for the automated recognition of the largest common substructure among a diverse set of chemical structures. This approach is based on a substructure search technique. Five different search levels which were defined with weighted graph representation of the chemical structures are available in the search. The search level can be specified interactively. Applications to structure-activity problems, including sweetners and opiates are presented to illustrate the abilities of the program.
X-Ray and Infrared Studies of Lead Apatites

The cell constants and infrared spectra of lead apatites have been investigated. The lowering of the molecular symmetry Td of the phosphate ion, and the nature and extent of changes in vibration frequencies of lead apatites with the ionic substitution of PO43− by AsO43− and VO43− are discussed.
EVALUATION OF DIFFERENT STRATEGIES FOR INDUCTION OF CHILLING TOLERANCE IN SPRING MAIZE USING MORINGA LEAF EXTRACTS

Spring maize is highly sensitive to low temperatures during the early development of seedlings and to high temperatures during its reproductive stage. Different strategies are being used to minimize the adverse effects of temperature extremes. Therefore, a field experiment was conducted to enhance the performance of spring hybrid maize by seed priming (3% MLE) and transplanting 20 and 30-day-old seedlings. Seed priming with moringa leaf extract (MLE) significantly enhanced stand establishment in both direct sowing and in transplanting, as indicated by the higher emergence percentage, emergence index, and lower time taken to start of emergence and mean emergence time. Minimum days from sowing to tasseling and silking were found in MLE primed 20-day-old seedlings grown in a nursery. However, all the agronomic parameters increased considerably with MLE priming of 20-day-old seedlings. Thus, MLE priming reduced chilling damage by improving stand establishment, whereas transplanting 20-day-old seedlings further enhanced the agronomic traits, yield, and quality of maize. However, the perfor-mance of maize plants from 30-day-old transplanted seedling and direct sowing was substandard.
Electrostress Diffusion Coupling Model for Polyelectrolyte Gels

To describe the deformation dynamics of polyelectrolyte gel, we formulate the electrostress diffusion coupling model. The model describes the interplay of the deformation of gel, permeation of water, and the transport of ions. The model gives a microscopic expression for the Onsager coefficient and allows us to discuss the effect of ionic radius. The model is then applied to the bending dynamics of a thin strip of ionic gels under stepwise application of electric field. The model qualitatively explains the relaxation behavior of an ionic gel (Nafion 117) for various kinds of ions including large counterions such as TEA+ (tetraethylammonium).
Machine vision technology for detecting the external defects of fruits — a review

Abstract Machine vision is a rapid, consistent and objective inspection technique, which has expanded into many diverse industries. Its speed and accuracy provide one alternative for an automated, non-destructive and cost-effective technique to accomplish ever-increasing production and quality requirements. This method of inspection has found applications in the agricultural industry, including the inspection and grading of fruits. The presence of skin defects is one of the most influential factors in the price of fruit, since most consumer associate quality with a good appearance and the total absence of external defects. However, defect is more difficult than colour, shape and size to be inspected and graded. In this paper, current applications of machine vision in fruit external defects detection are briefly reviewed. Some detection technologies were presented. These technologies include image processing methods based on fruit two-dimensional and three-dimensional (3D) information, and hyperspectral and multispectral imaging. In addition, their advantages and disadvantages are also discussed. Development of multi-camera combination imaging systems will ensure that computer vision technique continues to meet the accuracy and quality requirements needed in this highly competitive and challenging fruit industry. However, reducing of processing time and merging analysis of different type of images will be still a challenge since the combination systems are more complicated in a real-time application.
On the Temperature Dependence of Isosteric Heats of Water Sorption in Dehydrated Foods

The usual procedures for calculating isosteric heats of sorption by the application of the Clausius-Clapeyron equation (e.g. sorption isosteres or the intregated form) to isotherms at different temperatures, was examined. For almost all foods studied the magnitude of the heat curves seemed to be dependent on the temperature interval used for its calculation. However for some foods the relative differences in the isosteric heat curves were much more marked than in others. The observed behavior may be tentatively attributed to changes occurring in foods subjected to increased temperatures in the “Semi-dry” or “dry” state. These changes may be identified with among others cross-linking and denaturation of proteins, nonenzymatic browning reactions and the like.
Two‐particle vibrational excitations in molecular crystals

In this paper we utilize a two‐particle band model to describe cooperative vibrational excitations and vibrational overtones in molecular crystals of diatomic molecules. The cooperative vibrational excitation involves a two‐vibron continuum, while the overtone corresponds to a two‐vibron bound state. The problem of two‐particle vibrational excitations was shown to be equivalent to the perturbation of a band by a local potential, whose strength is determined by the intramolecular anharmonicity. Model calculations were performed for a three‐dimensional, semicircular density of states, resulting in transparent expressions for the energetics and intensities, which were utilized subsequently to provide a self‐consistent analysis of the available experimental results. In all these cases, the local perturbation is sufficiently strong to ensure the appearance of a bound overtone state outside the two‐particle band. Finally, we consider the effects of structural disorder on two‐vibron states, which provide a diagn.
Crystal engineering with a purine rare tautomer: structures and luminescence properties

Cadmium, a metal known to be toxic to living systems through unfavorable interactions with biomolecules, interacts with purine nucleobases through N7 imino nitrogen and induces modifications by altering amino–imino tautomeric equilibrium. Herein, we report unique crystallographic signatures of cadmium complexes of N9-benzyl-N6-methoxyadenine, a rare imino tautomer of adenine. These complexes exhibit a variety of coordination numbers and spatial geometries, highlighting the ability of nucleobases to form diverse supramolecular architectures, enabling better understanding of metal–DNA interactions. The Cd2+ ion in complex 1 has a coordination number of four with a distorted tetrahedral geometry, while 2 and 3 are hexa-coordinated, where 2 displays a discrete distorted octahedron geometry and 3 appears as a dinuclear complex. On the other hand, complex 4 exhibits a less common hepta-coordination mode with a distorted pentagonal bipyramidal geometry. The luminescence properties of these cadmium complexes are also reported.
Synthesis, crystal structure, and comparison of two new uranyl vanadate layered compounds: M6(UO2)5(VO4)2O5 with M = Na, K

Abstract Two new alkali uranyl vanadates, M6(UO2)5(VO4)2O5 with M=Na, K, have been synthesized by solid state reactions and their structures determined from single-crystal X-ray diffraction data. They crystallize in the monoclinic system with space group P21/c. Unit cell b, c, and β parameters are almost identical in both compounds while the a parameter in the Na compound is doubled: Na—a=12.584(1) A, b=24.360(2) A, c=7.050(1) A, β=100.61(1)°, V=2124.2 A3, Z=4, Dmes=5.60(2) g/cm3, Dcal=5.63 g/cm3; K—a=6.856(1) A, b=24.797(3) A, c=7.135(1) A, β=98.79(8)°, V=1198.8 A3, Z=2, Dmes=5.25(2) g/cm3, Dcal=5.25 g/cm3. A full-matrix least-squares refinement yielded, respectively, R=0.039, Rw=0.043 and R=0.037; Rw=0.046 for 3293 and 2096 independent reflections with I>3σ collected on a Philips PW 1100 diffractometer (MoKα radiation). Both structures are characterized by [(UO2)5(VO4)2O5x]6n−n corrugated layers parallel to the (100) plane. The layers are built up from VO4 tetrahedra, UO7 pentagonal bipyramids, and UO6 distorted octahedra. The UO7 pentagonal bipyramids are associated by sharing opposite equatorial edges to form zig-zag infinite chains (UO5)n parallel to the c axis. These chains are linked together on one side by VO4 tetrahedra and on other side by UO6 octahedra and UO7 corner sharing. Both structures differ simply by the symmetry of the layers. The unit cell contains one centrosymmetric layer in the K compound, whereas in the two-layer unit cell of the Na compound two noncentrosymmetric consecutive layers are related by an inversion center. The layers appear to be held together by the alkali ions. The mobility of the M+ ions within the interlayer space in M6(UO2)5(VO4)2O5 and carnotite analog compounds is compared.
Pathways of phosphorus transformations in soils of differing pedogenesis

Nine different organic and inorganic soil phosphorus fractions were obtained by a sequential extraction of samples from 168 USDASCS benchmark soils, representing eight soil orders of the Soil Taxonomy. The distribution of P across the different fractions (resin, bicarbonate, hydroxide, sonification-2nd hydroxide, acid, and acidperoxide digest fractions with separate organic and inorganic P determinations) and their relationships to other soil chemical properties were used to evaluate the effects of different soil development on phosphorus composition. Correlation and regression analyses of P distribution and chemical analyses confirmed the partial dependence of organic matter accumulation on available forms of P. Weathering indicators such as base saturation were related to the formation of secondary P forms. The relative proportions of available and stable as well as organic and inorganic P forms were dependent upon soil chemical properties and related to soil taxonomy. Path analysis of relationships between labile and stable P forms showed that in Mollisols much of the labile resin extractable P was derived from inorganic bicarbonate and hydroxide extractable P forms. In more weathered Ultisols, 80% of the variability in labile P was accounted for by organic P forms, suggesting that mineralization of organic P may be a major determinant of P fertility in these soils. Additional Index Words: organic phosphorus, inorganic phosphates, sequential phosphorus extraction, soil taxonomy, path-analysis. View complete article To view this complete article, insert Disc 4 then click button8
Multichromophoric dendrimers as single-photon sources: A single-molecule study

Single-molecule fluorescence spectroscopy was performed on a number of multi-peryleneimide substituted polyphenylene dendrimers for the purpose of investigating the parameters which influence the efficiency of the dendrimers as single-photon sources at room temperature. Analysis of fluorescence intensity, lifetime, and interphoton arrival time distribution revealed that all measured first-generation dendrimers behave as single-photon emitters when more than one chromophore is excited by a single excitation pulse regardless of the number of constituent chromophores. This is a result of efficient singlet-singlet annihilation, which becomes less efficient in higher-generation dendrimers when the interchromophoric distance increases. The efficiency of the investigated dendrimers as single-photon sources depends on several other parameters, such as the nature of the surrounding polymer matrix, the number of chromophores, and the extent of interchromophoric interactions. These parameters mainly affect the frequency of singlet-triplet annihilation, which in turn dominates the quality of these multichromophoric dendrimers as single-photon sources. The results reported here are important not only for the design of single-photon sources based on single organic molecules but also for a fundamental understanding of natural and artificial multichromophoric systems.
Magnetic and magneto‐optical properties of rare‐earth transition‐metal alloys containing Dy, Ho, Fe, Co

Amorphous rare‐earth transition‐metal alloys of composition REl−xTMx with RE=Dy, Ho; TM=Fe,Co and 0<x<1 and Dyl−x(Fe,Co)x were prepared by evaporation. The saturation magnetization, uniaxial anisotropy, coercivity, and Faraday rotation were investigated as a function of composition and temperature. Also, the spectral variation of the Kerr rotation was measured. The magnetization data indicate a strong dispersion of the RE moments due to randomly oriented local crystal field axes. The strong turndown of the Curie temperature for the Fe‐rich alloys suggests that an additional dispersion is present in the Fe subnetwork. The mean field theory was used to analyze the temperature variation of the magnetization yielding smaller TM spin values and exchange coupling constants as compared with those of the Gd and Tb analogs. The uniaxial anisotropy constant Ku for Dy‐Co based alloys was found to vary with the square of the Dy subnetwork magnetization as predicted by the random single‐ion theory. The anisotropy of D.
Chain transfer in anionic polymerization. Determination of chain-transfer constants by using carbon-14-labeled chain transfer agents

A method is described in which 14C-labeled chain-transfer agents are employed to measure chain-transfer constants in anionic polymerization as low as 10−6. Each chain-transfer step incorporates one molecule of the chain-transfer agent into the polymer so that measurement of the activity and conversion allows evaluation of the chain-transfer constant. This method is independent of the initiator concentration and efficiency, making the technique especially useful when problems with the initiator are encountered. The experimental procedure is described in detail for the case of chain transfer to toluene in the n-butyllithium-initiated polymerization of styrene, where CRH was found to be 5 × 10−6. A mathematical treatment is given showing the relationship between the degree of polymerization (DPn) and chain transfer.
Cross-linking Amine-Modified Silica Aerogels with Epoxies: Mechanically Strong Lightweight Porous Materials

The mesoporous surfaces of TMOS-derived silica aerogels have been modified with amines by copolymerization of TMOS with APTES. The amine sites have become anchors for cross-linking the nanoparticles of the skeletal backbone of the aerogel by attachment of di-, tri-, and tetra-functional epoxies. The resulting conformal coatings increase the density of the native aerogels by a factor of 2−3 but the strength of the resulting materials may increase by more than 2 orders of magnitude. Processing variables such as the amount of APTES used to make the gels, the epoxy type and concentration used for cross-linking, and the cross-linking temperature and time were varied according to a multivariable design-of-experiments (DOE) model. It was found that while elastic modulus follows a similar trend with density, maximum strength is attained neither at the maximum density nor at the highest concentration of −NH2 groups, suggesting surface saturation effects. Aerogels cross-linked with the trifunctional epoxide always .
Excess Partial Molar Enthalpy of 1-Propanol in 1-Propanol−NaCl−H2O at 25 °C: The Effect of NaCl on Molecular Organization of H2O†

Excess partial molar enthalpies of 1-propanol, H1PE, in 1-propanol−NaCl−H2O were measured directly, accurately, and in small increments in mole fraction of 1-propanol, x1P, at 25 °C in the range xNaCl < 0.04. xNaCl is the mole fraction of NaCl. The enthalpic interaction function, H1P-1PE, between 1-propanol molecules was then evaluated. H1P-1PE is a convenient, model-free measure for the intermolecular interaction in terms of enthalpy. The behavior of these thermodynamic quantities was compared with that of the binary 1-propanol−H2O. Based on the knowledge accumulated in our laboratory on the binary aqueous 1-propanol, the effect of NaCl on H2O became apparent. Our tentative conclusions are that (1) a NaCl molecule “binds” to seven or eight molecules of H2O on dissolving into H2O, and (2) the reminder of bulk H2O away from solute NaCl is not affected and stays almost the same as pure H2O.
The Effects of Pressure Difference in Nozzle’s two Phase Flow on the Quality of Exhaust Mixture

In the most application of nozzle with gas-liquid two-phase flow, the quality of mixture in exhaust of nozzle is the most important parameter as well as the flow velocity. On the other hand, in some industrial application, such as water injection in forced induction (turbocharged or supercharged) internal combustion engine the spray quality is the main goal of designing. In this case and for improving of injection performance the air-water two phase nozzle injection flow is more remarkable subject. There are two ways for this purpose, premixed or un-premixed air-water in entrance of the nozzle. In both cases, the nozzle not only has to accelerate gas and liquid to extra high velocity, but also it is supposed to have a high quality mixture in exhaust of nozzle. In this study, the turbulent gas-liquid two-phase premixed/un-premixed flow through the nozzle is simulated by the Eulerian-Lagrangian approach. The gas phase is treated as a continuum by solving the time-averaged Navier-Stokes equations, while the liquid as a dispersed phase is solved by tracking a large number of droplets through the calculated flow field. The pressure, velocity and Mach number profiles as well as air flow-rates and particle residence time inside the nozzle for various back pressure values have been computed. This work has been validated by comparison of pressure profiles and air flow-rates between simulated results and available experimental results for un-premixed nozzle flow.
Constituents of Houttuyniae Cordata and the Crystal Structure of Vomifoliol

In the isolation of the constituents of Houttuyniae cordata, ten pure compounds including 1,3,5-tridecanoylbenzene (1), caryophyllene oxide (2), several sterones (3-6) and sesamin (7), plus long-chain alcohol mixture, a steroidal mixture and 4-hydroxybenzoic acid methyl ester (8), vomifoliol (9) [or Blumenol A], quercetin-3-O-β-L-rhamnoside (10), were isolated from the aerial parts of H cordata. Their structures were determined by spectral analysis. Among them, compound 1 is for the first time isolated from nature. We describe here the spectral analysis of 1, and the X-ray determination of the relative stereochemistry of vomifoliol (9).
Lattice Boltzmann Investigations on Drag Reduction in Microchannel Flow With Bionic Surfaces

In this paper, four types of micro-patterned surfaces, which are covered with ridge-shaped grooves, V-shaped grooves, shield-shaped grooves and straight slot grooves, are employed to investigate the drag reduction effect. Lattice Boltzmann method (LBM), a new numerical approach on mescoscopic level, is used to conduct the numerical simulations. The micro-grooved surfaces possess the drag reduction performance because the micro-structure affects the flow beahviours. The existence of the vortices formed within the grooves not only decrease the shear force between fluid and walls but also reduce the contact area between fluid and walls, which can lead to a reduction of pressure loss. The different grooved-surfaces have different degrees of drag reduction abilities: ridge-shaped grooves > V-shaped grooves > shield shaped grooves > straight slot grooves. Besides, the geometrical optimizations for the ridge-shaped grooves, which show the highest drag reduction performance, are performed as well. The results suggest that, for the purpose of drag reduction, the ridge-shaped grooves with smaller width-height ratio are recommended for the lower Reynolds number flow while the ridge-shape grooves with larger width-height ratio are more suitable for the larger Reynolds number flow.Copyright © 2011 by ASME