32,218 research outputs found

    Explicit large nuclear charge limit of electronic ground states for Li, Be, B, C, N, O, F, Ne and basic aspects of the periodic table

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    This paper is concerned with the Schrödinger equation for atoms and ions with N=1N=1 to 10 electrons. In the asymptotic limit of large nuclear charge ZZ, we determine explicitly the low-lying energy levels and eigenstates. The asymptotic energies and wavefunctions are in good quantitative agreement with experimental data for positive ions, and in excellent qualitative agreement even for neutral atoms (Z=NZ=N). In particular, the predicted ground state spin and angular momentum quantum numbers (1S^1S for He, Be, Ne, 2S^2S for H and Li, 4S^4S for N, 2P^2P for B and F, and 3P^3P for C and O) agree with experiment in every case. The asymptotic Schrödinger ground states agree, up to small corrections, with the semiempirical hydrogen orbital configurations developed by Bohr, Hund, and Slater to explain the periodic table. In rare cases where our results deviate from this picture, such as the ordering of the lowest 1Do^1D^o and 3So^3S^o states of the carbon isoelectronic sequence, experiment confirms our predictions and not Hund's

    Food for Thought: Genetically Modified Seeds as De Facto Standard Essential Patents

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    For several years, courts have been improperly calculating damages in cases involving the unlicensed use of genetically-modified (GM) seed technology. In particular, when courts determine patent damages based on the hypothetical negotiation method, they err in exaggerating these damages to a point where no rational negotiator would agree. In response, we propose a limited affirmative defense of an implied license due to the patent’s status as a de facto standard essential patent. To be classified as a de facto standard essential patent, the farmer must prove three elements that reflect the peculiarities of GM seeds used in farming: (1) dominance, (2) impracticability, and (3) necessary to fulfill a basic need. Based on the approaches used by courts and standard setting organizations in licensing standard essential patents in technological fields such as cell phones and software, designation of some GM seeds as standard essential patents allows the courts to imply a license from patentees to farmers on reasonable and non-discriminatory (RAND) terms. Doing so shifts the case from a tort-based patent infringement suit to a breach of contract dispute and alters the damages regime from one based in compensation, deterrence, and punishment (a tort approach) to one based solely in compensation (a contractual approach). As a result of this novel proposal, the damages calculations in these suits return to economic reality

    Long-range-corrected hybrids including RPA correlation

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    We recently demonstrated a connection between the random phase approximation (RPA) and coupled cluster theory [J. Chem. Phys. 129, 231101 (2008)]. Based on this result, we here propose and test a simple scheme for introducing long-range RPA correlation into density functional theory. Our method provides good thermochemical results and models van derWaals interactions accurately.Comment: Accepted version of the manuscrip

    Optical Quantum Computation with Perpetually Coupled Spins

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    The possibility of using strongly and continuously interacting spins for quantum computation has recently been discussed. Here we present a simple optical scheme that achieves this goal while avoiding the drawbacks of earlier proposals. We employ a third state, accessed by a classical laser field, to create an effective barrier to information transfer. The mechanism proves to be highly efficient both for continuous and pulsed laser modes; moreover it is very robust, tolerating high decay rates for the excited states. The approach is applicable to a broad range of systems, in particular dense structures such as solid state self-assembled (e.g., molecular) devices. Importantly, there are existing structures upon which `first step' experiments could be immediately performed.Comment: 5 pages including 3 figures. Updated to published versio

    Evaluation of Adult Cottonwood Leaf Beetle, \u3ci\u3eChrysomela Scripta\u3c/i\u3e (Coleoptera: Chrysomelidae), Feeding Preference for Hybrid Poplars

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    Foliage from the Leuce section of Populus was rejected for feeding by Chrysomela scripta adults in a choice test involving 12 hybrid poplar clones. Adults showed a feeding preference for the foliage from the Tacamahaca clones when compared to the Aigeiros clones

    IMPACT OF THE 2002 BIOTERRORISM ACT ON THE NEW JERSEY FOOD INDUSTRY

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    This paper provides an overview of the four key sections of the Public Health Security and Bioterrorism Preparedness and Response Act of 2002, with regard to Administrative Detention (Section 303), Facilities Registration (Section 305), Records and Maintenance (Section 306), and Prior Notice of Food Imports (Section 307). The potential impacts of the Bioterrorism Act on the food industry are examined through qualitative analysis of industry submissions to the Food and Drug Administration (FDA) docket for each provision, and quantitatively through survey results, which were administered online by the Food Institute (FI) of Woodbridge, NJ and analyzed by Rutgers, Food Policy Institute (FPI). Of the four key sections from the Bioterrorism Act that most affect the food industry, stakeholders were surveyed on two sections, Prior notice of Food Imports and Facilities Registration. While survey responses reveal that many food firms are aware of pending Bioterrorism Act policies, few however, have taken action towards compliance. Facilities registration is touted as the least cumbersome in terms of compliance. Results indicate that 50 percent of food industry professionals surveyed were not aware that many food firms must register with the FDA by the 12 December 2003 deadline; and, 20 percent, while aware of the facilities registration deadline, have done nothing to prepare. Being unprepared for and subsequently complying with Bioterrorism Act rules is an overarching concern, which is apparent in both the survey results and docket summaries. Moreover, upon review of docket submissions to the FDA, it seems that food firms are generally sympathetic towards the need for increased food system security; however, the impact of the Bioterrorism Act can be both daunting and costly. Many perceive that significant changes to capitol costs will be required to meet FDA standards.Agribusiness,

    A Search for New Physics with the BEACON Mission

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    The primary objective of the Beyond Einstein Advanced Coherent Optical Network (BEACON) mission is a search for new physics beyond general relativity by measuring the curvature of relativistic space-time around Earth. This curvature is characterized by the Eddington parameter \gamma -- the most fundamental relativistic gravity parameter and a direct measure for the presence of new physical interactions. BEACON will achieve an accuracy of 1 x 10^{-9} in measuring the parameter \gamma, thereby going a factor of 30,000 beyond the present best result involving the Cassini spacecraft. Secondary mission objectives include: (i) a direct measurement of the "frame-dragging" and geodetic precessions in the Earth's rotational gravitomagnetic field, to 0.05% and 0.03% accuracy correspondingly, (ii) first measurement of gravity's non-linear effects on light and corresponding 2nd order spatial metric's effects to 0.01% accuracy. BEACON will lead to robust advances in tests of fundamental physics -- this mission could discover a violation or extension of general relativity and/or reveal the presence of an additional long range interaction in physics. BEACON will provide crucial information to separate modern scalar-tensor theories of gravity from general relativity, probe possible ways for gravity quantization, and test modern theories of cosmological evolution.Comment: 8 pages, 2 figures, 2 table

    Structural Covariance in the Hard Sphere Fluid

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    We study the joint variability of structural information in a hard sphere fluid biased to avoid crystallisation and form fivefold symmetric geometric motifs. We show that the structural covariance matrix approach, originally proposed for on-lattice liquids [Ronceray and Harrowell, JCP 2016], can be meaningfully employed to understand structural relationships between different motifs and can predict, within the linear-response regime, structural changes related to motifs distinct from that used to bias the system
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