cssi/SciSciGPT-SciSciNet huggingface dataset:
A New Metastable Thin‐Film Strontium Tantalate Perovskite

A novel Sr-Ta-O perovskite phase has been synthesized by a chemical preparation route and crystallized on Pt-coated SiO{sub 2}/Si substrates at {minus} 800 C. The phase was isolated as a thin film only (not as a polycrystalline powder) and is likely metastable. SEM, EDS, XRD, EPR, and Raman analyses suggest this phase is cation-deficient, having the formula Sr{sub x}Ta{sub x}O{sub 3} (X {approximately} 0.85). X-ray Rietveld analysis indicates the structure to be a simple-cubic perovskite-type lattice; Pm3m space group, a = 3.955(2) {angstrom}, V = 61.86 {angstrom}{sup 3}, Z = 1. Electrical property measurements recorded a dielectric constant k of {approximately} 16 with a tan {delta} of 0.04.
Price competition in e-tailing under service and recognition differentiation

The Internet has significantly increased the bargaining power of consumers. Many online shopping search engines allow consumers to find most retailers that sell a specific product, compare product prices, and review detailed store ratings. With competition just a click away, online retailers have little control over where consumers would shop. Offering the lowest price alone does not always guarantee that consumers will come and buy at your site. Other non-price attributes, such as service quality and a merchant's brand recognition, also play important roles in helping online retailers to build competitive advantages. In this paper, we present a model of price competition that assumes e-tailers can mainly differentiate themselves by providing different levels of service and by establishing a different online recognition. Closed-form equilibrium solutions are obtained for the different scenarios that may arise in this model. Based on such solutions, we give managerial insights on how e-tailers should position themselves when parameters such as service cost, service levels, and recognition are varied.
Initial scientific results from phase-referenced astrometry of sub-arcsecond binaries

The Palomar Testbed Interferometer has observed several binary star systems whose separations fall between the interferometric coherence length (a few hundredths of an arcsecond) and the typical atmospheric seeing limit of one arcsecond. Using phase-referencing techniques we measure the relative separations of the systems to precisions of a few tens of micro-arcseconds. We present the first scientific results of these observations, including the astrometric detection of the faint third stellar component of the kappa Pegasi system.
Kaluza-Klein 5D Ideas Made Fully Geometric

After the 1916 success of general relativity that explained gravity by adding time as a fourth dimension, physicists have been trying to explain other physical fields by adding extra dimensions. In 1921, Kaluza and Klein has shown that under certain conditions like cylindricity (∂ gij/∂ x5 = 0), the addition of the 5th dimension can explain the electromagnetic field. The problem with this approach is that while the model itself is geometric, conditions like cylindricity are not geometric. This problem was partly solved by Einstein and Bergman who proposed, in their 1938 paper, that the 5th dimension is compactified into a small circle S1 so that in the resulting cylindric 5D space-time R4× S1 the dependence on x5 is not macroscopically noticeable. We show that if, in all definitions of vectors, tensors, etc., we replace R4 with R4× S1, then conditions like cylindricity automatically follow – i.e., these conditions become fully geometric.
Application of differential synthesis to design of multiaxis stability augmentation systems.

Differential synthesis technique application to design of multiaxis stability augmentation systems for aerospace vehicles
Electrochemical studies of potassium ferrate(VI)

The electrochemical reduction of potassium ferrate(VI) in 6N-KOH occurs in three steps, at approximately +0.3, −0.7, and −1.4 V vs. Hg/HgO, 6N-KOH. The first reduction appears as a voltammetric wave on a platinum electrode and the second two are observed as polarographic waves with a dropping mercury electrode. Controlled potential coulometric, voltammetric, and chronopotentiometric studies indicate the reduction proceeds stepwise first to iron(III), then to iron(II) and finally to iron(0).
Endurance exercise training reduces cardiac sodium/calcium exchanger expression in animals susceptible to ventricular fibrillation.

Aim: Increased sodium/calcium exchanger activity (NCX1, an important regulator of cardiomyocyte cystolic calcium) may provoke arrhythmias. Exercise training can decrease NCX1 expression in animals with heart failure improving cytosolic calcium regulation, and could thereby reduce the risk for ventricular fibrillation (VF). Methods: To test this hypothesis, a 2-min coronary occlusion was made during the last min. of exercise in dogs with healed myocardial infarctions; 23 had VF (S, susceptible) and 13 did not (R, resistant). The animals were randomly assigned to either 10-wk exercise training (progressively increasing treadmill running) (S n = 9; R n = 8) or 10-wk sedentary (S n = 14; R n = 5) groups. At the end of the 10-wk period, the exercise + ischemia test provoked VF in sedentary but not trained susceptible dogs. On a subsequent day, cardiac tissue was harvested and NCX1 protein expression was determined by Western blot. Results: In the sedentary group, NCX1 expression was significantly (ANOVA, P<0.05) higher in susceptible compared to resistant dogs. In contrast, NCX1 levels were similar in the exercise trained resistant and susceptible animals. Conclusion: These data suggest that exercise training can restore a more normal NCX1 level in dogs susceptible to ventricular fibrillation, improving cystolic calcium regulation and could thereby reduce the risk for sudden death following myocardial infarction.
Opioid self-administration and rem sleep EEG power spectra

Abstract This study was designed to explore the possible existence of temporal electrophysiological changes in the central nervous system in dependent rats that were self-administering morphine, methadone, l -alpha-acetylmethadol (LAAM), nor-LAAM or dinor-LAAM. Adult, female, Sprague-Dawley rats were implanted with chronic cortical and temporalis muscle electrodes and intravenous (i.v.) cannulas for drug administration. Tolerance and physical dependence were induced by automatic hourly intravenous injections of increasing doses of morphine. Rats were then trained to lever press to selfadminister morphine on a fixed ratio 20 schedule of reinforcement. For some of the rats, morphine was then replaced with methadone, l -alpha-acetylmethadol (LAAM), nor-LAAM or dinor-LAAM. At least l week was allowed for the establishment of stabilized self-injection patterns. Samples of the EEG of successive rapid eye movement (REM) sleep episodes which occurred between self-injections were subjected to power spectral analyses using a Nicolet MED-80 system. During self-administration of these narcotic drugs, the first REM sleep episode following an injection had the faster peak EEG frequency. The peak EEG frequencies of the successive REM sleep episodes during an interinjection interval declined in a linear fashion towards the next injection. Differences in the slopes of the linear peak EEG frequency declines of the different narcotic drugs appear to correlate with differences in the pharmacokinetic profiles. These EEG changes are not related to lever pressing activity since analogous EEG frequency changes were seen in physically dependent rats receiving automatic morphine injections. The slowing in peak EEG frequencies may reflect a decline in brain levels of the respective drug leading to changes in the central nervous system that precede “drug-seeking behavior”.
Neutron diffraction analysis at 15 K and ab initio molecular orbital calculations for α-cyanoacetohydrazide: A crystal structure with a high energy conformer

Abstract The crystal structure of α-cyanoacetohydrazide, C 3 H 5 N 3 O, is refined using single-crystal neutron diffraction data at 15 K. Nuclear equilibrium geometries of the isolated molecules are calculated using GAUSSIAN-82 for the eight possible conformers having C s symmetry. The conformation observed in the crystal has the eighth highest calculated energy, 36.6 kJ mol −1 above the lowest energy conformer, and the largest calculated dipole moment, 8.6 D, with a HF/6-31G* basis. In the crystal the molecule is distorted from the ideal C s symmetry. These distortions add another 20.3 kJ mol −1 in energy, calculated with HF/6-31G*. All the hydrogens, including the CH, are involved in intermolecular hydrogen-bonding which is unusual in that it is formed entirely by three-center bonds. These bonds form a network which includes dimer and chain configurations.
Searching for primordial black hole dark matter with pulsar timing arrays

We discuss the possibility of detecting the presence of primordial black holes (PBHs), such as those that might account for galactic dark matter, using modification of pulsar timing residuals when PBHs pass within ~1000 AU and impart impulse accelerations to the Earth. With this technique, PBHs with masses around MPBH ~ 1025 g (~0.1 lunar masses) can be detected. Currently, the constraints on the abundance of such dark matter candidates are weak. A 30 yr-long monitoring campaign with the proposed Square Kilometer Array can rule out a PBH fraction more than ~1/10 in the solar neighborhood in the form of dark matter with mass MPBH ~ 1025 g.
Asymmetric electrophilic amination of chiral phosphorus-stabilized anions

Abstract The asymmetric electrophilic amination of phosphorus-stabilized anions derived from chiral oxazaphosphorinanes and diazaphospholidines is described. Trisyl azide is the reagent of choice for the amination process. The reaction is shown to be dependent on auxiliary structure, nature of the P-alkyl substituent and choice of amination procedure. Using the oxazaphosphorinanes 1a and cis-1e a high level of asymmetric induction can be achieved. Scalemic cis-1e provides the α-aminophosphonic acid 13 with 92% e.e. in the (S) antipode. The implications for conformation and effect of auxiliary structure on stereoselectivity are discussed.
X-ray observations and infrared identification of the transient 7.8 s X-ray binary pulsar XTE J1829-098

XMM-Newton and Chandra observations of the transient 7.8 s pulsar XTE J1829-098 are used to characterize its pulse shape and spectrum, and to facilitate a search for an optical or infrared counterpart. In outburst, the absorbed, hard X-ray spectrum with Γ = 0.76 ± 0.13 and NH = (6.0 ± 0.6) × 1022 cm-2 is typical of X-ray binary pulsars. The precise Chandra localization in a faint state leads to the identification of a probable infrared counterpart at R.A. = 18h29m43.98s, decl. = -09°51'23'' (J2000.0), with magnitudes K = 12.7, H = 13.9, I > 21.9, and R > 23.2. If this is a highly reddened O or B star, we estimate a distance of 10 kpc, at which the maximum observed X-ray luminosity is 2 × 1036 ergs s-1, typical of Be X-ray transients or wind-fed systems. The minimum observed luminosity is 3 × 1032(d/10 kpc)2 ergs s-1. We cannot rule out the possibility that the companion is a red giant. The two known X-ray outbursts of XTE J1829-098 are separated by ≈1.3 yr, which may be the orbital period or a multiple of it, with the neutron star in an eccentric orbit. We also studied a late M giant long-period variable that we found only 9'' from the X-ray position. It has a pulsation period of ≈1.5 yr, but is not the companion of the X-ray source.
A piecewise linear finite element discretization of the diffusion equation for arbitrary polyhedral grids

We develop a piecewise linear (PWL) Galerkin finite element spatial discretization for the multi-dimensional radiation diffusion equation. It uses recently introduced piecewise linear weight and basis functions in the finite element approximation and it can be applied on arbitrary polygonal (2D) or polyhedral (3D) grids. We first demonstrate some analytical properties of the PWL method and perform a simple mode analysis to compare the PWL method with Palmer's vertex-centered finite-volume method and with a bilinear continuous finite element method. We then show that this new PWL method gives solutions comparable to those from Palmer's. However, since the PWL method produces a symmetric positive-definite coefficient matrix, it should be substantially more computationally efficient than Palmer's method, which produces an asymmetric matrix. We conclude that the Galerkin PWL method is an attractive option for solving diffusion equations on unstructured grids.
Non-supersymmetric, multi-center solutions with topological flux

We find an infinite class of non-supersymmetric multi-center solutions to the STU model in five-dimensional ungauged supergravity coupled to two vector multiplets. The solutions are obtained by solving a system of linear equations on a class of Ricci-scalar-flat Kahler manifolds studied by LeBrun. After imposing an additional U(1) isometry in the base, we solve the axisymmetric SU(∞) Toda equation and obtain explicit supergravity solutions containing arbitrary numbers of 2-cycles with cohomological fluxes of all three flavors. This improves upon a previous result where only two of the three fluxes were topologically non-trivial. Imposing regularity and absence of closed timelike curves, we obtain “bubble equations” highly reminiscent of those known in the supersymmetric case. Thus we extend much of the analysis done for BPS bubbling solutions to this new family of non-supersymmetric bubbling solutions.
Total curvature and simple pursuit on domains of curvature bounded above

We show how circumradius and asymptotic behavior of curves in cat(0) and cat(K) spaces (K > 0) are controlled by growth rates of total curvature. We apply our results to pursuit and evasion games of capture type with simple pursuit motion, generalizing results that are known for convex Euclidean domains, and obtaining results that are new for convex Euclidean domains and hold on playing fields vastly more general than these.
A model for moving university research to industrial application

Summary form only given. The Rutgers University Center for Computer Aids for Industrial Productivity (CAIP) is one of several tightly focused advanced technology centers chartered by the New Jersey Commission on Science and Technology. CAIP's focus is industrial application of leading-edge computing technology. The Center is an industrial consortium. The budget supports about 70 researchers. Each member company has a representative on the Board of Directors for the Center. The Board meets quarterly to review the research program, to advise on industry needs, to ready paths to application for research, and to become familiar with graduate students completing their degree programs. The Center also works closely with new start-up companies to provide laboratory, computing, and consulting assistance in their initial phases. In its sixth year, the Center had placed over 60 advanced-degree graduates in its affiliated industries, helped to attract over not contained in/implied by in funding for new start-up businesses, and continually moves relevant research results, some of which are covered by patents, to its member companies. The author reviews the structure and research activities of the Center, and describes several in-progress transfers of technology to industry. >
Organizing and visualizing database data using parallel coordinates

In this paper, we describe a data organization and axis grouping technique for managing parallel coordinate plots. A database visualization model is created as an intermediary between the data and the visualization. On the visualization side, axes within a parallel coordinate plot are put into groups which can be represented by a new axis in the plot, while the members of the group are hidden. Methods are presented for building these groups and displaying their axes, each with their own advantages and disadvantages. Lastly, a working system which uses these techniques to visualize data from a database is presented.
Neutral Hydrogen in Arp 158

We present 21 cm observations of Arp 158. We have performed a study of the neutral hydrogen (H I) to help us understand the overall formation and evolution of this system. This is a disturbed system with distinct optical knots connected by a linear structure embedded in luminous material. There is also a diffuse spray to the southeast. The H I seems to be made up of three distinct, kinematically separate systems. Arp 158 bears a certain optical resemblance to NGC 520 (Arp 157), which has been identified as a mid-stage merger. From our 21 cm observations of Arp 158, we also see a comparable H I content with NGC 520. These similarities suggest that Arp 158 is also an intermediate-stage merger.
4,5,6,7-Tetrachlorobenzo[d][1,3,2]dioxaborol- 2-ol as an effective catalyst for the amide condensation of sterically demanding carboxylic acids.

[reaction: see text] 4,5,6,7-Tetrachlorobenzo[d][1,3,2]dioxaborole (4a) and 4,5,6,7-tetrachlorobenzo[d][1,3,2]dioxaborol-2-ol (4b) are effective catalysts for the dehydrative amide condensation between an equimolar mixture of carboxylic acids and amines. In particular, these catalysts are greatly superior to 3,5-bis(trifluoromethyl)phenylboronic acid (1) for the amide condensation of sterically demanding carboxylic acids. In contrast, 4c, which is prepared from a 1:2 molar mixture of B(OH)(3) and tetrachlorocatechol, is effective as a Lewis acid-assisted Bronsted acid (LBA) catalyst for Ritter reaction.
Nonprotein amino acids from Cycas revoluta

Abstract Two nonprotein amino acids, cycasindene and cycasthioamide, along with eight known nonprotein amino acids, were isolated from the seeds of Cycas revoluta Thumb. The structures of cycasindene and cycasthioamide were elucidated as 3-[3′-amino-indenyl-2′]-alanine (1) and N -[glycinyl-alaninyl-11-thio]-5-one-pipecolic acid ( 2 ) by chemical and spectral methods.
A new statistic to evaluate imputation reliability.

Background As the amount of data from genome wide association studies grows dramatically, many interesting scientific questions require imputation to combine or expand datasets. However, there are two situations for which imputation has been problematic: (1) polymorphisms with low minor allele frequency (MAF), and (2) datasets where subjects are genotyped on different platforms. Traditional measures of imputation cannot effectively address these problems.
Numerical computation of real or complex elliptic integrals

Algorithms for numerical computation of symmetric elliptic integrals of all three kinds are improved in several ways and extended to complex values of the variables (with some restrictions in the case of the integral of the third kind). Numerical check values, consistency checks, and relations to Legendre's integrals and Bulirsch's integrals are included.
Risk, the financial market, and macroeconomic equilibrium*

Growing recognition of the importance of stock market phenomena to the real economy underscores the need for models linking exogenous uncertainty, asset market performance, and the rest of the economy in an optimizing framework without certainty equivalence. This paper constructs a three-agent model with continuous-time stochastic variables, uncertain private production and government expenditure, and forward-looking rational agents. The growth rate of output, physical capital accumulation, financial asset returns, and uncertain inflation are determined as functions of the exogenous uncertainty in the economy. Analysis of the model finds that increased risk associated with government policy often reverses in an explainable way the conventional comparative static predictions of nonstochastic macro models.
Single-electron transmetalation in organoboron cross-coupling by photoredox/nickel dual catalysis

The routine application of C(sp3)-hybridized nucleophiles in cross-coupling reactions remains an unsolved challenge in organic chemistry. The sluggish transmetalation rates observed for the preferred organoboron reagents in such transformations are a consequence of the two-electron mechanism underlying the standard catalytic approach. We describe a mechanistically distinct single-electron transfer-based strategy for the activation of organoboron reagents toward transmetalation that exhibits complementary reactivity patterns. Application of an iridium photoredox catalyst in tandem with a nickel catalyst effects the cross-coupling of potassium alkoxyalkyl- and benzyltrifluoroborates with an array of aryl bromides under exceptionally mild conditions (visible light, ambient temperature, no strong base). The transformation has been extended to the asymmetric and stereoconvergent cross-coupling of a secondary benzyltrifluoroborate.
Manifolds in random media: a variational approach to the spatial probability distribution

We develop a new variational scheme to approximate the position dependent spatial probability distribution of a zero dimensional manifold in a random medium. This celebrated'toy-model'is associated via a mapping with directed polymers in 1+1 dimension, and also describes features of the commensurate-incommensurate phase transition. It consists of a pointlike «interface» in one dimension subject to a combination of a harmonic potential plus a random potential with long range spatial correlations. The variational approach we develop gives far better results for the tail of the spatial distribution than the Hamiltonian version, developed by Mezard and Parisi, as compared with numerical simulations for a range of temperatures
Diastereoselective bromodifluoromethylation and difluoromethylation of chiral imide enolates via insertion of difluorocarbene

Abstract Lithium enolates of chiral N -acyloxazolidinones reacted with dibromodifluoromethane and bromodifluoromethane to give α-bromodifluoromethyl and α-difluoromethyl carboximides, respectively, with good diastereomeric excess. These reactions proceed not via a radical mechanism but via an ionic chain mechanism involving insertion of difluorocarbene.
Neopentane Conversion Catalyzed by Pd in L-Zeolite: Effects of Protons, Ions, and Zeolite Structure

Abstract The conversion of 2,2-dimethylpropane (neopentane) has been studied over zeolite-L-supported Pd catalysts; the results are compared with data for Pd on zeolite Y. Variation of the charge compensating ion (Li + , K + , or Ca 2+ ) in L has only a moderate effect on the catalytic parameters, due either to variations in the heat of physisorption or to "electronic" effects on Pd. The reduction temperature, TR, of Pd/L samples that have previously been calcined at 250°C, strongly affects the catalytic performance: after T R = 250°C, sufficient NH 3 ligands of the ion exchanged Pd(NH 3 ) 2+ 4 ions survive to neutralize the protons that are formed during reduction; catalytic activity then increases during reaction while NH + 4 ions decompose and Pd-proton adducts of high catalytic activity are formed. At T R = 400°C, the NH 3 ligands are destroyed and this catalyst is stable and very active. Activity, selectivity, and kinetic parameters depend on the structure of the support; apparent activation energies, E a , are in the range of 45-55 kcal/mol for Pd/Y, but 75-90 kcal/mol for Pd/L. A linear relation between E a and log of the preexponential factor is obtained. While classical pore-diffusion operates in Y, single - file diffusion appears more likely in L; i.e., channels tend to be plugged with physisorbed molecules at low temperature. The difficult of primary reaction products to escape from the pores correlates with a higher fraction of secondary products observed for Pd/L vis-a-vis Pd/SiO 2 . It is conceivable that different diffusion types also contribute to the different E a values for zeolites with three-dimensional or unidimensional channel systems.
The Marchenko representation of reflectionless Jacobi and Schrödinger operators

We consider Jacobi matrices and Schrodinger operators that are reflectionless on an interval. We give a systematic development of a certain parametrization of this class, in terms of suitable spectral data, that is due to Marchenko. Then some applications of these ideas are discussed.
The factory and the beehive. II. Activity and rotation in Praesepe and the Hyades

Open clusters are collections of stars with a single, well-determined age, and can be used to investigate the connections between angular-momentum evolution and magnetic activity over a star's lifetime. We present the results of a comparative study of the relationship between stellar rotation and activity in two benchmark open clusters: Praesepe and the Hyades. As they have the same age and roughly solar metallicity, these clusters serve as an ideal laboratory for testing the agreement between theoretical and empirical rotation-activity relations at ≈600 Myr. We have compiled a sample of 720 spectra—more than half of which are new observations—for 516 high-confidence members of Praesepe; we have also obtained 139 new spectra for 130 high-confidence Hyads. We have also collected rotation periods (P {sub rot}) for 135 Praesepe members and 87 Hyads. To compare Hα emission, an indicator of chromospheric activity, as a function of color, mass, and Rossby number R{sub o} , we first calculate an expanded set of χ values, with which we can obtain the Hα to bolometric luminosity ratio, L {sub Hα}/L {sub bol}, even when spectra are not flux-calibrated and/or stars lack reliable distances. Our χ values cover a broader range of stellar masses and colorsmore » (roughly equivalent to spectral types from K0 to M9), and exhibit better agreement between independent calculations, than existing values. Unlike previous authors, we find no difference between the two clusters in their Hα equivalent width or L {sub Hα}/L {sub bol} distributions, and therefore take the merged Hα and P {sub rot} data to be representative of 600 Myr old stars. Our analysis shows that Hα activity in these stars is saturated for R{sub o}≤0.11{sub −0.03}{sup +0.02}. Above that value activity declines as a power-law with slope β=−0.73{sub −0.12}{sup +0.16}, before dropping off rapidly at R{sub o} ≈ 0.4. These data provide a useful anchor for calibrating the age-activity-rotation relation beyond 600 Myr.« less
Nonisothermal Band Model Theory

Abstract Theoretical formulations of radiation band models for general nonuniform optical paths are presented. The models are framed within the statistical band model for an array of Lorentz lines and an inverse line strength distribution. Radiative transfer for an isolated line in a general nonuniform medium and the statistical model for a uniform optical path are reviewed in order to provide the foundation required for the band model formulations. Two approaches to the development of these models are taken. The first is based on making approximations to such radiative transfer functions as transmittance or equivalent width and yields models equivalent or similar to the traditional Curtis-Godson approximation. The second treats approximations to the spatial derivatives of these functions. From the standpoint of computing line or band radiance, the spatial derivatives are more fundamental quantities than the transfer functions themselves; consequently, these latter “derivative approximations” are instrinsically more accurate than the Curtis-Godson type approximations. All of the models are formulated to give the spatial derivative of the mean equivalent width function W (s) δ in the form 1 δ d W (s) ds =c(s)p(s) k (s)y(s) , where c(s), p(s) and k(s) are the concentration, total pressure and absorption band model parameter, respectively, at the local path position s. The functional form of the derivative function y(s) is derived for each of the models. In general, y(s) is a function of both local and path-averaged (subscript e) band model parameters. These local and averaged parameters are used to define a dimensionless optical depth parameter x e = u k e β e and three nonuniformity indexes ρ= γ γ e , r= β β e and θ = δ e δ (γ is line width, ḡd is the mean line spacing band model parameter, and β = 2μ γ γ ). The explicit manner in which these parameters enter into the various functional forms for y(s) is derived and discussed. The introduction of the parameter q is an important aspect of the new models and is an explicit measure of nonisothermality along the optical path. In addition to the traditional Curtis-Godson definitions for the effective parameters ke and βe, new definitions for the path averages γe and δe are derived. These new definitions are obtained from the fundamental properties of the assumed inverse line strength distribution. A summary of all the models is given as a table of relevant equations for use in practical calculations.
Rigidity of secondary characteristic classes

The topic of this paper is the rigidity of secondary characteristic classes associated to a flat connection on a differentiable manifold M. Viewing the connection as a Lie-algebra valued one-form for a Lie algebra g, it is proven that if the Leibniz cohomology of g vanishes, then all secondary characteristic classes for g are rigid. Moreover, in the case when g is the Lie algebra of formal vector fields and M supports a family of codimension one foliations, the image of a characteristic map from HL4(g) to H∗dR(M) is computed, where HL∗ denotes Leibniz cohomology and H∗dR denotes de Rham cohomology.
Maximal extension of Schwarzschild metric

There is presented a particularly simple transformation of the Schwarzschild metric into new coordinates, whereby the "spherical singularity" is removed and the maximal singularity-free extension is clearly exhibited.
Addressing Women's Fear of Victimization in Transportation Settings A Survey of U.S. Transit Agencies

Past research has shown that transit passengers' fears and concerns about safety influence their travel decisions. While the relationship between women's fear of crime and public space has been the focus of considerable research, transit environments—which are especially threatening to female passengers—have received much less attention. This study examines the issue of women's safety on transit through a survey of U.S. transit operators. The findings show that most respondents believe women have distinct safety and security needs, but most do not think agencies should put specific programs into place to address these needs. In addition, only a handful of agencies currently have programs that target the safety and security needs of women. This survey suggests that there is a significant mismatch between the safety and security needs and desires of female passengers and the types and locations of strategies that transit agencies use.
Bulk and rare earth abundances in the Luna-16 soil levels A and D

Abstract Abundances of the major, minor and trace elements (SiO2, O, TiO2, Al2O3, FeO, CaO, Na2O, K2O, Cr2O3, MnO, Sc, V, Co, La, Sm, Eu, Yb and Lu) have been determined via sequential INAA (instrumental neutron activation analysis) in two Luna-16 soils, levels A (∼ 7 cm) and D (∼ 30 cm depth). Abundances of the bulk elements in Luna-16 soils generally agree with the values reported by Vinogradov. Elemental abundances of both bulk and trace elements are nearly the same for the two A and D soil levels. With the exception of lower TiO2 in Luna-16 soil (Sea of Fertility), the overall chemical composition of Luna-16 soil is more similar to Apollo 11 soil (Sea of Tranquillity) than to soils from Apollo 12 (Oceanus Procellarum) and Apollo 14 (Fra Mauro). Consistent with findings for Apollo 11 and 12 rocks and soil, the Luna-16 fines are depleted in oxygen with respect to terrestrial igneous rocks of comparable Si content. The chondrite normalized REE (rare earth elements) distribution patterns of Luna-16 soils are similar to those of Apollo 11 soil and they are quite different from the light REE enriched patterns of Apollo 12 and 14 soils. The REE abundances and Sm/Eu ratio in Luna-16 soils are significantly different from the higher values of Apollo 11, 12 and 14 soils. Sm abundances, which are approximately proportional to the total REE abundances, of 9.0 ppm found in Luna-16 soils are compared to 12.6, 16–31 and 31 ppm in Apollo 11, 12 and 14 soils, respectively. A Sm/Eu ratio of 3.9 observed in Luna-16 soils is compared to 7.4 ± 0.4, 9.7 ± 0.3 and 11.6 ± 0.2 in Apollo 11, 12 and 14 soils, respectively. Relative to the Sm/Eu ratio of 2.7 in chondrite meteorites, Luna-16 soil has the lowest Eu depletion of all lunar soils measured to date.
Industry Self-Regulation Without Sanctions: The Chemical Industry's Responsible Care Program

Industry self-regulation—the voluntary association of firms to control their collective action—has been proposed as a complement to government regulation. Proponents argue that the establishment of...
Selection of RIB targets using ion implantation at the Holifield Radioactive Ion Beam Facility

Among several major challenges posed by generating and accelerating adequate intensities of RIBs, selection of the most appropriate target material is perhaps the most difficult because of the requisite fast and selective thermal release of minute amounts of the short-lived product atoms from the ISOL target in the presence of bulk amounts of target material. Experimental studies are under way at the Oak Ridge National Laboratory (ORNL) which are designed to measure the time evolution of implanted elements diffused from refractory target materials which are candidates for forming radioactive ion beams (RIBs) at the Holifield Radioactive Ion Beam Facility (HRIBF). The diffusion coefficients are derived by comparing experimental data with numerical solutions to a one-dimensional form of Fick`s second law for ion implanted distributions. In this report, we describe the experimental arrangement, experimental procedures, and provide time release data and diffusion coefficients for releasing ion implanted {sup 37}Cl from Zr{sub 5}Si{sub 3} and {sup 75}As, {sup 79}Br, and {sup 78}Se from Zr{sub 5}Ge{sub 3} and estimates of the diffusion coefficients for{sup 35}Cl, {sup 63}Cu, {sup 65}Cu, {sup 69}Ga and {sup 71}Ga diffused from BN; {sup 35}Cl, {sup 63}Cu, {sup 65}Cu, {sup 69}Ga, {sup 75}As, and {sup 78}Se diffused from C;more » {sup 35}Cl, {sup 68}Cu, {sup 69}Ga, {sup 75}As, and {sup 78}Se diffused from Ta.« less
Periodic solutions of certain hybrid delay-differential equations and their corresponding difference equations

In this paper we use a method due to Carvalho (A method to investigate bifurcation of periodic solution in retarded differential equations, J. Differ. Equ. Appl. 4 (1998), pp. 17–27) to obtain conditions for the existence of nonconstant periodic solutions of certain systems of hybrid delay-differential equations. We first deal with a scalar equation of Lotka–Valterra type; then a system of two equations in two unknowns that could model the interactions of two identical neurons. It will be seen that such solutions are determined by solutions of corresponding difference equations. Another paper in which this method is used is by Cooke and Ladeira (Applying Carvalho's method to find periodic solutions of difference equations, J. Differ. Equ. Appl. 2 (1996), pp. 105–115). We first state Carvalho's result.
Approximations for large scale closed queueing networks

Abstract Evaluation of closed queueing networks with product form solutions is very time-consuming if the population sizes or the network size is large. This paper provides an analysis of an approximation technique, based upon mean value analysis which requires considerably less computation time, and yet achieves a high degree of accuracy. The approximates are unique in some feasible regions. Error analysis and illustrative examples are provided.
X-Ray Light Curves and Accretion Disk Structure of EX Hydrae

We present X-ray light curves for the cataclysmic variable EX Hydrae obtained with the Chandra High Energy Transmission Grating Spectrometer and the Extreme Ultraviolet Explorer Deep Survey photometer. We confirm earlier results on the shape and amplitude of the binary light curve and discuss a new feature: the phase of the minimum in the binary light curve, associated with absorption by the bulge on the accretion disk, increases with wavelength. We discuss several scenarios that could account for this trend and conclude that, most likely, the ionization state of the bulge gas is not constant, but rather decreases with binary phase. We also conclude that photoionization of the bulge by radiation originating from the white dwarf is not the main source of ionization, but that it is heated by shocks originating from the interaction between the in-flowing material from the companion and the accretion disk. The findings in this paper provide a strong test for accretion disk models in close binary systems.
A novel diphosphorus-molybdenum ring system

Abstract The reaction of ArPCl2 (Ar = 2,4,6-t-Bu3C6H2) with K[Mo(CO)3(η-C5H5)] affords Ar(H)PP(Cl)Ar (1), ArP[Mo(CO)2(η-C5H5)]2 (2), ArPPAr, ArPH2 and Ar(H)PP(H)Ar. By means of X-ray crystallography, it was established that the Mo2P ring of 2 involves a planar phosphorus geometry, a slight degree of MoP multiple bonding, and a MoMo single bond. Thermolysis of the original reaction mixture produced the P2Mo ring compound ArPP(H)(Ar)[μ2-Mo(CO)2(η-C5H5)] (3). The structure of 3 was determined by X-ray diffraction.
The radius of Titan from Pioneer Saturn data

The radius of Titan has been determined from Pioneer Saturn observations taken September 2, 1979. The data sets, one in the red (0.64 µm) and one in the blue (0.44 µm), yield radii of 2840±25 km and 2880±22 km, respectively. The discrepancy between the radius values in the two colors is felt to be the consequence of an optically thin submicron haze above the nominal haze layer. The altitude difference between the red and blue limb is 40±20 km. Using a cloud model derived from the Pioneer Saturn data, the lunar occultation radius (Elliot et al., 1975) has been revised to 2845±40 km, in good agreement with the present result. A lower limit of 1.37 g cm−3 can now be set on Titan's bulk density, using the red radius at the haze top. The actual bulk density probably falls in the range 1.65–1.85 g cm−3 for an atmosphere of 150- to 250-km thickness below the red limb.
Density dependence of in-medium nucleon-nucleon cross sections

The lowest-order correction of the density dependence of in-medium nucleon-nucleon cross sections is obtained from geometrical considerations of Pauli-blocking effects. As a by-product, it is shown that the medium corrections imply an 1/E energy dependence of the density-dependent term.
Investigation of the Rh-Catalyzed Asymmetric Reductive Aldol Reaction. Expanded Scope Based on Reaction Analysis

A series of experiments are described that suggest that the Rh-catalyzed reductive aldol reaction proceeds by addition of a Rh(I) hydride, generated in situ, to the reacting acrylate followed by a stereochemistry-controlling aldol addition reaction. On the basis of this hypothesis, reaction conditions are engineered that allow for increased substrate scope.
Spreading of Lagrangian Regularity on Rational Invariant Tori

Let P h be a self-adjoint semiclassical pseudodifferential operator on a manifold M such that the bicharacteristic flow of the principal symbol on T*M is completely integrable and the subprincipal symbol of P h vanishes. Consider a semiclassical family of eigenfunctions, or, more generally, quasimodes u h of P h . We show that on a nondegenerate rational invariant torus, Lagrangian regularity of u h (regularity under test operators characteristic on the torus) propagates both along bicharacteristics, and also in an additional “diffractive” manner. In particular, in addition to propagating along null bicharacteristics, regularity fills in the interiors of small annular tubes of bicharacteristics.
Constraining conformal field theories with a slightly broken higher spin symmetry

We consider three-dimensional conformal field theories that have a higher spin symmetry that is slightly broken. The theories have a large-N limit in the sense that the operators separate into single trace and multitrace and obey the usual large-N factorization properties. We assume that the spectrum of single trace operators is similar to the one that one obtains in the Vasiliev theories. Namely the only single trace operators are the higher spin currents plus an additional scalar. The anomalous dimensions of the higher spin currents are of the order 1/N. Using the slightly broken higher spin symmetry, we constrain the three-point functions of the theories to a leading order in N. We show that there are two families of solutions. One family can be realized as a theory of N fermions with an O(N) Chern?Simons gauge field, the other as an N bosons plus the Chern?Simons gauge field. The family of solutions is parametrized by the 't Hooft coupling. At special parity preserving points, we obtain the critical O(N) models: the Wilson?Fisher one and the Gross?Neveu one. Our analysis also fixes the on-shell three-point functions of Vasiliev's theory on AdS4 or dS4.
AdS/CFT beyond the unitarity bound

Scalars in AdS d+1 with squared masses in the Breitenlohner-Freedman window $$ - {d^{{2}}}/{4} \leqslant {m^{{2}}} < - {d^{{2}}}/{4} + {1} $$ (in units with the AdS scale l set to 1) are known to enjoy a variety of boundary conditions. For larger masses $$ {m^{{2}}} > - {d^{{2}}}/{4} + {1} $$ , unitarity bounds in possible dual CFTs suggest that such general boundary conditions should lead to ghosts. We show that this is not always the case as, for conformally-invariant boundary conditions in Poincare AdS that would naively violate unitarity bounds, the system is generically ghost-free. Conflicts with unitarity bounds are avoided due to the presence of unexpected pure gauge modes and an associated infrared divergence. The expected ghosts appear when the IR divergence is removed either by deforming these boundary conditions or considering global AdS.
Reformulation of the LDA+U method for a local orbital basis

We present a local orbital approach to the evaluation of the on-site repulsion energy $U$ for use in the $\mathrm{LDA}+U$ method of Anisimov and co-workers. Our objectives are to make the method more firmly based, to concentrate primarily on ground-state properties rather than spectra, and to test the method in cases where only modest changes in orbital occupations are expected, as well as for highly correlated materials. Because of these objectives, we employ a differential definition of $U$. We also define a matrix $\mathbf{U}$, which we find is very dependent on the environment of the atom in question. The formulation is applied to evaluate $U$ for transition-metal monoxides from VO to NiO using a local-orbital basis set. The resulting values of $U$ are typically only 40--65 % as large as values currently in use. We evaluate the $\mathbf{U}$ matrix for the ${e}_{g}$ and ${t}_{2g}$ subshells in paramagnetic FeO, and illustrate the very different charge responses of the ${e}_{g}$ and ${t}_{2g}$ states. The sensitivity of the method to the choice of the $d$ orbitals, and to the basis set in general, is discussed.
Homogeneous bilayer graphene film based flexible transparent conductor

Graphene is considered as a promising candidate to replace conventional transparent conductors due to its low opacity, high carrier mobility and flexible structure. Multi-layer graphene or stacked single layer graphenes have been investigated in the past but both have their drawbacks. The uniformity of multi-layer graphene is still questionable, and single layer graphene stacks require many transfer processes to achieve sufficiently low sheet resistance. In this work, bilayer graphene film grown with low pressure chemical vapor deposition was used as a transparent conductor for the first time. The technique was demonstrated to be highly efficient in fabricating a conductive and uniform transparent conductor compared to multi-layer or single layer graphene. Four transfers of bilayer graphene yielded a transparent conducting film with a sheet resistance of 180 Ω□ at a transmittance of 83%. In addition, bilayer graphene films transferred onto the plastic substrate showed remarkable robustness against bending, with sheet resistance change less than 15% at 2.14% strain, a 20-fold improvement over commercial indium oxide films.
Classes of automata and transitive closure

A study is made of the classes of predicates accepted by three types of multitape Turing machine. In order of decreasing acceptance powers, these are the general Turing machine, the linear-bounded automaton, and the two-way multitape nonwriting automaton. Each class is shown to consist of all and only those predicates which can be defined by a corresponding class of predicate calculus formulas based on catenation, and involving as logical operators conjunction, disjunction, and a type of transitive closure on predicates of 2n variables.
Use of a Readily Removable Auxiliary Group for the Synthesis of Pyrrolidones by the Palladium‐Catalyzed Intramolecular Amination of Unactivated γ C(sp3) ? H Bonds

Easy on, easy off: Directing groups found to promote the palladium-catalyzed amination of γ C(sp(3) )H and C(sp(2) )H bonds of secondary amides included 5-methoxy-8-aminoquinoline, which can be removed under mild conditions (see scheme; CAN=ceric ammonium nitrate). In conjunction with a β-CH methylation or γ-CH arylation step, the γ-C(sp(3) )H amination provided access to complex pyrrolidones from readily available precursors.
Development of (Trimethylsilyl)ethyl Ester Protected Enolates and Applications in Palladium-Catalyzed Enantioselective Allylic Alkylation: Intermolecular Cross-Coupling of Functionalized Electrophiles

The development of (trimethylsilyl)ethyl ester protected enolates is reported. The application of this class of compounds in palladium-catalyzed asymmetric allylic alkylation is explored, yielding a variety of α-quaternary six- and seven-membered ketones and lactams. Independent coupling partner synthesis engenders enhanced allyl substrate scope relative to traditional β-ketoester substrates; highly functionalized α-quaternary ketones generated by the union of (trimethylsilyl)ethyl β-ketoesters and sensitive allylic alkylation coupling partners serve to demonstrate the utility of this method for complex fragment coupling.