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61.
Journal of Geographical Systems - As the volume, accuracy and precision of digital geographic information have increased, concerns regarding individual privacy and confidentiality have come to the...  相似文献   
62.
Rhodium, one of the least abundant of the Pt-group elements in the earth's crust, has the second highest concentration in seawater. This may be a consequence of strong complexing, perhaps kinetically restrained with time constants of the order of centuries to millenia. The element shows a nutrient-like distribution in waters of the Pacific Ocean. Pelagic and coastal sediments have Rh concentrations close to crustal values. There is a remarkable enrichment of Rh in ferromanganese minerals that cannot be explained by oxidative capture. Unlike the other Pt-group elements, Rh is enriched in the high temperature hydrothermal sulfide deposits as well as phosphorites.  相似文献   
63.
At COP21 in Paris, governments reiterated the importance of ‘non-Party’ contributions, placing big bets that the efforts of cities, regions, investors, companies, and other social groups will help keep average global warming limited to well under 2°C. However, there is little systematic knowledge concerning the performance of non-state and subnational efforts. We established a database of 52 climate actions launched at the 2014 UN Climate Summit in New York to assess output performance – that is, the production of relevant outputs – to understand whether they are likely to deliver social and environmental impacts. Moreover, we assess to which extent climate actions are implemented across developed and developing countries. We find that climate actions are starting to deliver, and output performance after one year is higher than one might expect from previous experiences with similar actions. However, differences exist between action areas: resilience actions have yet to produce specific outputs, whereas energy and industry actions perform above average. Furthermore, imbalances between developing and developed countries persist. While many actions target low-income and lower-middle-income economies, the implementation gap in these countries remains greater. More efforts are necessary to mobilize and implement actions that benefit the world’s most vulnerable people.

Policy relevance

Climate actions by non-state and subnational actors are an important complement to the multilateral climate regime and the associated contributions made by national governments. Although such actions hold much potential, we still know very little about how they could deliver in practice. This article addresses this knowledge gap, by showing how 52 climate actions announced at the UN Climate Summit in 2014 have performed thus far. Based on our analysis, we argue that the post-Paris action agenda for non-state and subnational climate action should (1) find more effective ways to incentivize private sector actors to engage in transnational climate governance through actions that seek to reduce greenhouse gas emissions and promote climate resilience in a tangible manner; (2) identify factors underlying effectiveness, to take appropriate measures to support underperforming climate actions; and (3) address the large implementation gap of climate actions in developing countries.  相似文献   

64.
Excavations in 1964 at the Pine Spring site in southwest Wyoming concluded that the site contains three cultural occupation levels; the earliest allegedly dates to the terminal Pleistocene and is associated with megafauna. However, excavations in 1998 and 2000, and analysis of the stratigraphy, AMS dates, micromorphology, and artifact carbonate isotopes, along with debitage refitting, density, orientation, inclination, burning, and trample damage, could not replicate the 1964 findings. A hiatus in deposition accounts for the highest density of artifacts, and the three original occupations are palimpsests. There is no unequivocal association between evidence of human activity and megafaunal remains. © 2006 Wiley Periodicals, Inc.  相似文献   
65.
Address ranges used in linear interpolation geocoding often have errors and omissions that result in input address numbers falling outside of known address ranges. Geocoding systems may match these input addresses to the closest available nearby address range and assign low confidence values (match scores) to increase match rates, but little is published describing the matching or scoring techniques used in these systems. This article sheds light on these practices by investigating the need for, technical approaches to, and utility of nearby matching methods used to increase match rates in geocode data. The scope of the problem is motivated by an analysis of a commonly used health dataset. The technical approach of a geocoding system that includes a nearby matching approach is described along with a method for scoring candidates based on spatially‐varying neighborhoods. This method, termed dynamic nearby reference feature scoring, identifies, scores, ranks, and returns the most probable candidate to which the input address feature belongs or is spatially near. This approach is evaluated against commercial systems to assess its effectiveness and resulting spatial accuracy. Results indicate this approach is viable for improving match rates while maintaining acceptable levels of spatial accuracy.  相似文献   
66.
The basic functionality and performance of a new Schlumberger active wireline heave compensation system on the JOIDES Resolution was evaluated during the sea trial and a 3-year period of the IODP Phase II operations. A suite of software programs was developed to enable real-time monitoring of the dynamics of logging tools, and assess the efficiency of wireline heave compensation during downhole operations. The evaluation of the system effectiveness was performed under normal logging conditions as well as during stationary tests. Logging data were analyzed for their overall quality and repeatability, and to assess the reliability of high-resolution data such as formation microscanner (FMS) electrical images. This revealed that the system reduces 65–80 % of displacement or 88–98 % variance of downhole tool motion in stationary mode under heave conditions of ±0.2–1.5 m and water depths of 300–4,500 m in open holes. Under similar water/heave conditions, the compensator system reduces tool displacement by 50–60 %, or 75–84 % variance in downhole tool motion during normal logging operations. Such compensation efficiency (CE) is comparable to previous compensation systems, but using advanced and upgradeable technologies, and provides 50–85 % heave motion and heave variance attenuation. Moreover, logging down/up at low speeds (300–600 m/h) reduces the system’s CE values by 15–20 %, and logging down at higher speeds (1,000–1,200 m/h) eliminates CE values by 55–65 %. Considering the high quality of the logging data collected, it is concluded that the new system can provide an improved level of compensation over previous systems. Also, if practically feasible, future integration of downhole cable dynamics as an input feedback into the current system could further improve its compensation efficiency during logging operations.  相似文献   
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69.
The analyses of plutonium isotopes in dated strata of polar ice sheets indicate that the241Pu/239+240Pu activity ratio produced in the U.S.-dominated nuclear tests during the 1950s was about 26, while that in the U.S.S.R.-dominated weapons tests in the early 1960s was between 12 and 14. This difference provides time horizons for sedimentary deposits. Further, the239Pu/240Pu ratio may show a similar difference in fallout values from these two periods of weapons testing and may provide an additional, and perhaps more sensitive, chronology for sediments.  相似文献   
70.
On the marine geochemistry of barium   总被引:6,自引:0,他引:6  
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