Calculating Nonlocal Optical Properties of Structures with Arbitrary Shape

In a recent Letter [Phys. Rev. Lett. 103, 097403 (2009)], we outlined a computational method to calculate the optical properties of structures with a spatially nonlocal dielectric function. In this Article, we detail the full method, and verify it against analytical results for cylindrical nanowires. Then, as examples of our method, we calculate the optical properties of Au nanostructures in one, two, and three dimensions. We first calculate the transmission, reflection, and absorption spectra of thin films. Because of their simplicity, these systems demonstrate clearly the longitudinal (or volume) plasmons characteristic of nonlocal effects, which result in anomalous absorption and plasmon blueshifting. We then study the optical properties of spherical nanoparticles, which also exhibit such nonlocal effects. Finally, we compare the maximum and average electric field enhancements around nanowires of various shapes to local theory predictions. We demonstrate that when nonlocal effects are included, significant decreases in such properties can occur.Comment: 30 pages, 12 figures, 1 tabl

Reallocation of federal multipurpose reservoirs: principles, policy and practice

Proceedings of the 2003 Georgia Water Resources Conference, held April 23-24, 2003, at the University of Georgia.Most federal reservoirs placed in operation throughout the United States over the past 50 or 60 years serve multiple objectives, typically flood control, hydropower, navigation, recreation, water quality protection, irrigation and municipal and industrial (M&I) water supply. In the initial reservoir planning and design stage, federal agencies such as the U.S. Army Corps of Engineers (USACE) or the U.S. Bureau of Reclamation (USBR) decide on the scale of the project to be built based on demands for water and storage that prevail at the time and are expected to prevail after construction. A critical step in the planning process is the development of operating rules designed to conjunctively meet these many demands given the scope and scale of the existing project. One of the criteria applied to formulate such operating rules is contribution to National Economic Development (NED). In the decades since their initial construction, relative demands for various services provided by federal reservoirs (expressed as society’s willingness to pay for those services) have changed, in some cases substantially. These changes may prompt reallocation, or modifications to reservoir operating rules that better satisfy the more valuable emerging uses. Needed operational changes sometimes come at the expense of less valuable uses, even though these less valuable uses may constitute originally-authorized purposes of the project. Irrespective of any rights to water and/or to storage conveyed by federal law, significant questions of fairness (equity) and of economic efficiency arise with respect to the distribution of project benefits, costs and environmental impacts that occur if society chooses to reallocate or chooses not to reallocate. Fairness questions center on intergenerational equity and on sustainability while efficiency questions center on net economic surplus, or net benefits, aggregated across project uses. The authors examine as a case study the pronounced shift in public demand from hydropower to M&I water supply in the southeastern United States, to illustrate the potential disparities between the overarching principles that guide federal planning and the policies and procedures historically (and often successfully) used in practice to implement small, incremental reallocations. The normally small differences between objective principles and practical outcomes can accumulate over time to unacceptable proportions, foreclosing options for adaptive management of the nation’s water resources infrastructure and threatening sustainability, equity and efficiency as a consequence

Fundamental Behavior of Electric Field Enhancements in the Gaps Between Closely Spaced Nanostructures

We demonstrate that the electric field enhancement that occurs in a gap between two closely spaced nanostructures, such as metallic nanoparticles, is the result of a transverse electromagnetic waveguide mode. We derive an explicit semianalytic equation for the enhancement as a function of gap size, which we show has a universal qualitative behavior in that it applies irrespective of the material or geometry of the nanostructures and even in the presence of surface plasmons. Examples of perfect electrically conducting and Ag thin-wire antennas and a dimer of Ag spheres are presented and discussed.Comment: 9 pages and 4 figure

经济学、熵和可持续性

经济学是一门在传统上讨论稀缺问题的学科。稀缺资源的配置（自然资源和劳动力）涉及到广泛的哲学问题——有关价值、偏好、效率以及权益的问题。近年来物理科学和生态科学的发展，导致了可持续性的看法，并随之带来了一个以往不被主流经济学家重点关注的新问题。Daly（1992a）把宏观经济规模这个问题，或者说较之环境经济的规模该有多大这个问题说成是“灿烂的反常现象”。因为，尽管单一的经济活动最优规模可以按照其净利润是最大的观点来确定，但对于最优宏观经济规模却没有一致同意的度量。这种反常现象在主流经济学家们中关于获得最优的各个时期间的资源分配（这是可持续性的最重要问题）的方法的不一致的意见中反映出来。争论提出了关于在新古典理论里规模问题是否已被充分地考虑，以及这个问题到底是否应该被考虑这样的基本问题。这场争论的核心问题（Burness et al. 1980; Ranson,1979, 1986; Swaney, 1985, 1986）是资源利用的新古典理论是否应该被修改以包含热力学的第二定律（也叫熵定律）。新古典理论目前包含第一定律（即能量守恒与物质守恒），它论证了表明理性的经济代理人的偏好的价格。籍以精确地反映资源稀缺的条件，及市场籍以有效分配稀缺资源的条件。但是，熵定律对所有的不仅仅由守恒反映的自然流程施加了一种额外的方向性约束。在经济计划及政策发展的预测中，如果第一定律的因素产生了稀缺资源显著地不精确的度量，那么熵就变得是与资源利用的经济学有关系的了。译者单位：河海大学商学院（常州213022

The effectiveness of a sustained nurse home visiting intervention for Aboriginal infants compared with non-Aboriginal infants and with Aboriginal infants receiving usual child health care : a quasi-experimental trial : the Bulundidi Gudaga study

Background: In Australia there is commitment to developing interventions that will 'Close the Gap' between the health and welfare of Indigenous and non-Indigenous Australians and recognition that early childhood interventions offer the greatest potential for long term change. Nurse led sustained home visiting programs are considered an effective way to deliver a health and parenting service, however there is little international or Australian evidence that demonstrates the effectiveness of these programs for Aboriginal infants. This protocol describes the Bulundidi Gudaga Study, a quasi-experimental design, comparing three cohorts of families from the Macarthur region in south western Sydney to explore the effectiveness of the Maternal Early Childhood Sustained Home-visiting (MECSH) program for Aboriginal families. Methods: Mothers were recruited when booking into the local hospital for perinatal care and families are followed up until child is age 4 years. Participants are from three distinct cohorts: Aboriginal MECSH intervention cohort (Group A), Non-Aboriginal MECSH intervention cohort (Group B) and Aboriginal non-intervention cohort (Group C). Eligible mothers were those identified as at risk during the Safe Start assessment conducted by antenatal clinic midwives. Mothers in Group A were eligible if they were pregnant with an Aboriginal infant. Mothers in Group B were eligible if they were pregnant with a non-Aboriginal infant. Mothers in Group C are part of the Gudaga descriptive cohort study and were recruited between October 2005 and May 2007. The difference in duration of breastfeeding, child body mass index, and child development outcomes at 18 months and 4 years of age will be measured as primary outcomes. We will also evaluate the intervention effect on secondary measures including: child dental health; the way the program is received; patterns of child health and illness; patterns of maternal health, health knowledge and behaviours; family and environmental conditions; and service usage for mothers and families. Discussion: Involving local Aboriginal research and intervention staff and investing in established relationships between the research team and the local Aboriginal community is enabling this study to generate evidence regarding the effectiveness of interventions that are feasible to implement and sustainable in the context of Aboriginal communities and local service systems. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12616001721493 Registered 14 Dec 2016. Retrospectively registered

The Next Frontier: Making Research More Reproducible

Science and engineering rest on the concept of reproducibility. An important question for any study is: are the results reproducible? Can the results be recreated independently by other researchers or professionals? Research results need to be independently reproduced and validated before they are accepted as fact or theory. Across numerous fields like psychology, computer systems, and water resources there are problems to reproduce research results (Aarts et al. 2015; Collberg et al. 2014; Hutton et al. 2016; Stagge et al. 2019; Stodden et al. 2018). This editorial examines the challenges to reproduce research results and suggests community practices to overcome these challenges. Coordination is needed among the authors, journals, funders and institutions that produce, publish, and report research. Making research more reproducible will allow researchers, professionals, and students to more quickly understand and apply research in follow-on efforts and advance the field

The XMM-SSC survey of hard-spectrum XMM-Newton sources 1: optically bright sources

We present optical and X-ray data for a sample of serendipitous XMM-Newton sources that are selected to have 0.5-2 keV vs 2-4.5 keV X-ray hardness ratios which are harder than the X-ray background. The sources have 2-4.5 keV X-ray flux >= 10^-14 cgs, and in this paper we examine a subsample of 42 optically bright (r < 21) sources; this subsample is 100 per cent spectroscopically identified. All but one of the optical counterparts are extragalactic, and we argue that the single exception, a Galactic M star, is probably a coincidental association. The X-ray spectra are consistent with heavily absorbed power laws (21.8 < log NH < 23.4), and all of them appear to be absorbed AGN. The majority of the sources show only narrow emission lines in their optical spectra, implying that they are type-2 AGN. Only a small fraction of the sources (7/42) show broad optical emission lines, and all of these have NH < 10^23 cm^-2. This implies that ratios of X-ray absorption to optical/UV extinction equivalent to > 100 times the Galactic gas-to-dust ratio are rare in AGN absorbers (at most a few percent of the population), and may be restricted to broad absorption-line QSOs. Seven objects appear to have an additional soft X-ray component in addition to the heavily absorbed power law. We consider the implications of our results in the light of the AGN unified scheme. We find that the soft components in narrow-line objects are consistent with the unified scheme provided that > 4 per cent of broad-line AGN have ionised absorbers that attenuate their soft X-ray flux by >50 per cent. In at least one of the X-ray absorbed, broad-line AGN in our sample the X-ray spectrum requires an ionised absorber, consistent with this picture.Comment: accepted for publication in MNRA

A Measurement of the Correlation of Galaxy Surveys with CMB Lensing Convergence Maps from the South Pole Telescope

We compare cosmic microwave background lensing convergence maps derived from South Pole Telescope (SPT) data with galaxy survey data from the Blanco Cosmology Survey, WISE, and a new large Spitzer/IRAC field designed to overlap with the SPT survey. Using optical and infrared catalogs covering between 17 and 68 deg^2 of sky, we detect a correlation between the SPT convergence maps and each of the galaxy density maps at >4σ, with zero correlation robustly ruled out in all cases. The amplitude and shape of the cross-power spectra are in good agreement with theoretical expectations and the measured galaxy bias is consistent with previous work. The detections reported here utilize a small fraction of the full 2500 deg^2 SPT survey data and serve as both a proof of principle of the technique and an illustration of the potential of this emerging cosmological probe

South Pole Telescope Detections of the Previously Unconfirmed Planck Early SZ Clusters in the Southern Hemisphere

We present South Pole Telescope (SPT) observations of the five galaxy cluster candidates in the southern hemisphere which were reported as unconfirmed in the Planck Early Sunyaev-Zel'dovich (ESZ) sample. One cluster candidate, PLCKESZ G255.62-46.16, is located in the 2500-square-degree SPT SZ survey region and was reported previously as SPT-CL J0411-4819. For the remaining four candidates, which are located outside of the SPT SZ survey region, we performed short, dedicated SPT observations. Each of these four candidates was strongly detected in maps made from these observations, with signal-to-noise ratios ranging from 6.3 to 13.8. We have observed these four candidates on the Magellan-Baade telescope and used these data to estimate cluster redshifts from the red sequence. Resulting redshifts range from 0.24 to 0.46. We report measurements of Y_0.75', the integrated Comptonization within a 0.75' radius, for all five candidates. We also report X-ray luminosities calculated from ROSAT All-Sky Survey catalog counts, as well as optical and improved SZ coordinates for each candidate. The combination of SPT SZ measurements, optical red-sequence measurements, and X-ray luminosity estimates demonstrates that these five Planck ESZ cluster candidates do indeed correspond to real galaxy clusters with redshifts and observable properties consistent with the rest of the ESZ sample.Comment: 7 emulateapj pages, 4 figures, 1 table. Revised to match published versio