Hot dry rock(HDR) is an important geothermal resource and clean energy source that may play an increasingly important role in future energy management. High-temperature HDR resources were recently detected in deep reg...Hot dry rock(HDR) is an important geothermal resource and clean energy source that may play an increasingly important role in future energy management. High-temperature HDR resources were recently detected in deep regions of the Gonghe Basin on the northeastern edge of the Tibetan Plateau, which led to a significant breakthrough in HDR resource exploration in China. This research analyzes the deep temperature distribution, radiogenic heat production, heat flow, and crustal thermal structure in the Qiaboqia Valley, Guide Plain, and Zhacanggou area of the Gonghe Basin based on geothermal exploration borehole logging data, rock thermophysical properties, and regional geophysical exploration data. The results are applied to discuss the heat accumulation mechanism of the HDR resources in the Gonghe Basin. The findings suggest that a low-velocity layer in the thickened crust of the Tibetan Plateau provides the most important source of constant intracrustal heat for the formation of HDR resources in the Gonghe Basin, whereas crustal thickening redistributes the concentrated layer of radioactive elements, which compensates for the relatively low heat production of the basal granite and serves as an important supplement to the heat of the HDR resources. The negative effect is that the downward curvature of the lithospheric upper mantle caused by crustal thickening leads to a small mantle heat flow component. As a result, the heat flows in the Qiaboqia Valley and Guide Plain of the Gonghe Basin are 106.2 and 77.6 m W/m2, respectively, in which the crust-mantle heat flow ratio of the former is 3.12:1, indicating a notably anomalous intracrustal thermal structure. In contrast, the crust-mantle heat flow ratio in the Guide Plain is 1.84:1, which reflects a typical hot crust-cold mantle thermal structure. The Guide Plain and Zhacanggou area show the same increasing temperature trend with depth, which reflects that their geothermal backgrounds and deep high-temperature environments are similar. These results provide important insight on the heat source mechanism of HDR resource formation in the Tibetan Plateau and useful guidance for future HDR resource exploration projects and target sites selection in similar areas.展开更多
AIM：To provide a side-by-side analysis of the summary of safety and effectiveness data（SSED）submitted to the FDA for the KAMRA and Raindrop corneal inlays for the correction of presbyopia.METHODS：SSED reports subm...AIM：To provide a side-by-side analysis of the summary of safety and effectiveness data（SSED）submitted to the FDA for the KAMRA and Raindrop corneal inlays for the correction of presbyopia.METHODS：SSED reports submitted to the FDA for KAMRA and Raindrop were compared with respect to loss of corrected distance visual acuity（CDVA）,adverse event rates,induction of astigmatism,retention of contrast sensitivity,stability of manifest refractive spherical equivalent（MRSE）,and achieved monocular uncorrected near visual acuity（UNVA）at 24mo.RESULTS：Totally 442/508 of KAMRA patients and344/373 Raindrop patients remained enrolled in the clinical trials at 24mo.The proportion of KAMRA and Raindrop patients who lost≥2 lines of CDVA at 24mo was 3.4%and1%,respectively.The adverse event rate was comparable between the devices.No significant inductions of astigmatism were noted.Both technologies induced a transient myopic shift in MRSE followed by a hyperopic shift and subsequent stabilization.Totally 87%of KAMRA and 98%of Raindrop patients attained a monocular UNVA of J5（20/40）or better at 24mo,28%of KAMRA and 67%of Raindrop patients attained a monocular UNVA of J1（20/20）or better at 24mo.CONCLUSION：Both devices can be considered safe and effective,however,the results of corneal inlay implantation are mixed,and long-term patient satisfaction will likely depend on subjective expectations about the capabilities of the inlays.Variability in surgical technique and postoperative care within and between the two clinical trials diminishes the comparative power of this article.展开更多
AIM: To evaluate the light adjustable lens (LAL) vs a standard monofocal lens in achieving target astigmatic refraction and improving postoperative uncorrected distance visual acuity (UDVA).METHODS: This randomized co...AIM: To evaluate the light adjustable lens (LAL) vs a standard monofocal lens in achieving target astigmatic refraction and improving postoperative uncorrected distance visual acuity (UDVA).METHODS: This randomized controlled clinical trial included 40 patients with pre-existing astigmatism and visually significant cataract. Twenty-eight patients received the LAL and 12 control patients received a monofocal intraocular lens (IOL) after cataract extraction at a single institution. The patients with the LAL underwent adjustment by ultraviolet (UV) light postoperatively plus subsequent lock-in procedures and all patients returned to clinic for follow up of study parameters at 6, 9, and 12mo. Manifest refraction, distance visual acuity, and adverse events were recorded at each visit. RESULTS: The mean cylinder before adjustment in eyes with the LAL was -0.89±0.58 D (-2.00 to 0.00 D) and -0.34±0.34 D (-1.25 to 0.00 D) after lock-in (P=1.68×10^-8). The mean cylinder in patients with the monofocal lens was -1.00±0.32 D (-1.50 to -0.50 D) at 17-21d postoperatively, which was statistically different from the LAL cylinder post lock-in (P=1.43×10^-6). UDVA in the LAL group was 20/20 or better in 79% of patients post lock-in with good stability over 12mo compared with 33% of the control patients with UDVA of 20/20 or better.CONCLUSION: These results demonstrate that the LAL is more effective in achieving target refractions and improving postoperative UDVA in patients with pre-existing corneal astigmatism than a standard monofocal lens.展开更多
A novel electrode design for the in situ generation of ozone in the reaction zone of a tubular reactor is described in this work.The ozone generator uses a porous inner electrode tube in the corona discharge assembly,...A novel electrode design for the in situ generation of ozone in the reaction zone of a tubular reactor is described in this work.The ozone generator uses a porous inner electrode tube in the corona discharge assembly,and the ozone generated around the outer periphery of the porous tube diffuses into the tubular reactor and reacts with the contaminants in the fluid that is being treated.A mathematical model that includes absorption and second order reaction in the film is developed to describe ozonation kinetics of a contaminant dye in the tubular reactor.The model describes the experimental data for dye decolorization,oxidation byproducts,dissolved ozone,and ozone gas concentrations well.Model analysis indicates that the fast dye decolorization reaction occurs partly in the liquid film and partly in the bulk fluid.The model can be used in the selection of appropriate gas-liquid contactors for efficient oxidation of contaminants in effluents.展开更多
Optimization of adaptive traffic signal timing is one of the most complex problems in traffic control systems. This paper presents an adaptive transit signal priority （TSP） strategy that applies the parallel genetic...Optimization of adaptive traffic signal timing is one of the most complex problems in traffic control systems. This paper presents an adaptive transit signal priority （TSP） strategy that applies the parallel genetic algorithm （PGA） to optimize adaptive traffic signal control in the presence of TSP. The method can optimize the phase plan, cycle length, and green splits at isolated intersections with consideration for the performance of both the transit and the general vehicles. A VISSIM （VISual SIMulation） simulation testbed was developed to evaluate the performance of the proposed PGA-based adaptive traffic signal control with TSP. The simulation results show that the PGA-based optimizer for adaptive TSP outperformed the fully actuated NEMA control in all test cases. The results also show that the PGA-based optimizer can produce TSP timing plans that benefit the transit vehicles while minimizing the impact of TSP on the general vehicles.展开更多
Desert resource environments(e.g.microclimates,food)are tied to limited,highly localized rainfall regimes which generate microgeographic variation in the life histories of inhabitants.Typically,enhanced growth rates,r...Desert resource environments(e.g.microclimates,food)are tied to limited,highly localized rainfall regimes which generate microgeographic variation in the life histories of inhabitants.Typically,enhanced growth rates,reproduction and survivorship are observed in response to increased resource availability in a variety of desert plants and short-lived animals.We examined the thermal ecology and reproduction of US federally threatened Mojave desert tortoises(Gopherus agassizii),long-lived and large-bodied ectotherms,at opposite ends of a 250-m elevation-related rainfall cline within Ivanpah Valley in the eastern Mojave Desert,California,USA.Biophysical operative environments in both the upper-elevation,“Cima,”and the lower-elevation,“Pumphouse,”plots corresponded with daily and seasonal patterns of incident solar radiation.Cima received 22%more rainfall and contained greater perennial vegetative cover,which conferred 5°C-cooler daytime shaded temperatures.In a monitored average rainfall year,Cima tortoises had longer potential activity periods by up to several hours and greater ephemeral forage.Enhanced resource availability in Cima was associated with larger-bodied females producing larger eggs,while still producing the same number of eggs as Pumphouse females.However,reproductive success was lower in Cima because 90%of eggs were depredated versus 11%in Pumphouse,indicating that predatory interactions produced counter-gradient variation in reproductive success across the rainfall cline.Land-use impacts on deserts(e.g.solar energy generation)are increasing rapidly,and conservation strategies designed to protect and recover threatened desert inhabitants,such as desert tortoises,should incorporate these strong ecosystem-level responses to regional resource variation in assessments of habitat for prospective development and mitigation efforts.展开更多
Dense cities represent biogeochemical hot spots along the shoreline,concentrating fixed nitrogen that is subsequently discharged into adjacent coastal receiving waters.Thus,the ecosystem services provided by natural s...Dense cities represent biogeochemical hot spots along the shoreline,concentrating fixed nitrogen that is subsequently discharged into adjacent coastal receiving waters.Thus,the ecosystem services provided by natural systems in highly urban environments can play a particularly important role in the global nitrogen cycle.In this paper,we review the recent literature on nitrogen regulation by temperate coastal ecosystems,with a focus on how the distinct physical and biogeochemical features of the urban landscape can affect the provision of this ecosystem service.We use Jamaica Bay,an ultra-urbanized coastal lagoon in the United States of America,as a demonstrative case study.Based on simple areal and tidal-based calculations,the natural systems of Jamaica Bay remove~24%of the reactive nitrogen discharged by wastewater treatment plants.However,this estimate does not represent the dynamic nature of urban nitrogen cycling represented in the recent literature and highlights key research needs and opportunities.Our review reveals that ecosystem-facilitated denitrification may be significant in even the most densely urbanized coastal landscapes,but critical uncertainties currently limit incorporation of this ecosystem service in environmental management.展开更多
基金supported by National Key R&D Program of China(Grant No.2018YFB1501803)。
文摘Hot dry rock(HDR) is an important geothermal resource and clean energy source that may play an increasingly important role in future energy management. High-temperature HDR resources were recently detected in deep regions of the Gonghe Basin on the northeastern edge of the Tibetan Plateau, which led to a significant breakthrough in HDR resource exploration in China. This research analyzes the deep temperature distribution, radiogenic heat production, heat flow, and crustal thermal structure in the Qiaboqia Valley, Guide Plain, and Zhacanggou area of the Gonghe Basin based on geothermal exploration borehole logging data, rock thermophysical properties, and regional geophysical exploration data. The results are applied to discuss the heat accumulation mechanism of the HDR resources in the Gonghe Basin. The findings suggest that a low-velocity layer in the thickened crust of the Tibetan Plateau provides the most important source of constant intracrustal heat for the formation of HDR resources in the Gonghe Basin, whereas crustal thickening redistributes the concentrated layer of radioactive elements, which compensates for the relatively low heat production of the basal granite and serves as an important supplement to the heat of the HDR resources. The negative effect is that the downward curvature of the lithospheric upper mantle caused by crustal thickening leads to a small mantle heat flow component. As a result, the heat flows in the Qiaboqia Valley and Guide Plain of the Gonghe Basin are 106.2 and 77.6 m W/m2, respectively, in which the crust-mantle heat flow ratio of the former is 3.12:1, indicating a notably anomalous intracrustal thermal structure. In contrast, the crust-mantle heat flow ratio in the Guide Plain is 1.84:1, which reflects a typical hot crust-cold mantle thermal structure. The Guide Plain and Zhacanggou area show the same increasing temperature trend with depth, which reflects that their geothermal backgrounds and deep high-temperature environments are similar. These results provide important insight on the heat source mechanism of HDR resource formation in the Tibetan Plateau and useful guidance for future HDR resource exploration projects and target sites selection in similar areas.
文摘AIM：To provide a side-by-side analysis of the summary of safety and effectiveness data（SSED）submitted to the FDA for the KAMRA and Raindrop corneal inlays for the correction of presbyopia.METHODS：SSED reports submitted to the FDA for KAMRA and Raindrop were compared with respect to loss of corrected distance visual acuity（CDVA）,adverse event rates,induction of astigmatism,retention of contrast sensitivity,stability of manifest refractive spherical equivalent（MRSE）,and achieved monocular uncorrected near visual acuity（UNVA）at 24mo.RESULTS：Totally 442/508 of KAMRA patients and344/373 Raindrop patients remained enrolled in the clinical trials at 24mo.The proportion of KAMRA and Raindrop patients who lost≥2 lines of CDVA at 24mo was 3.4%and1%,respectively.The adverse event rate was comparable between the devices.No significant inductions of astigmatism were noted.Both technologies induced a transient myopic shift in MRSE followed by a hyperopic shift and subsequent stabilization.Totally 87%of KAMRA and 98%of Raindrop patients attained a monocular UNVA of J5（20/40）or better at 24mo,28%of KAMRA and 67%of Raindrop patients attained a monocular UNVA of J1（20/20）or better at 24mo.CONCLUSION：Both devices can be considered safe and effective,however,the results of corneal inlay implantation are mixed,and long-term patient satisfaction will likely depend on subjective expectations about the capabilities of the inlays.Variability in surgical technique and postoperative care within and between the two clinical trials diminishes the comparative power of this article.
基金Supported by Research to Prevent Blindness(New York,New York)the clinical trial was sponsored by Rx Sight Inc.(formerly Calhoun Vision)
文摘AIM: To evaluate the light adjustable lens (LAL) vs a standard monofocal lens in achieving target astigmatic refraction and improving postoperative uncorrected distance visual acuity (UDVA).METHODS: This randomized controlled clinical trial included 40 patients with pre-existing astigmatism and visually significant cataract. Twenty-eight patients received the LAL and 12 control patients received a monofocal intraocular lens (IOL) after cataract extraction at a single institution. The patients with the LAL underwent adjustment by ultraviolet (UV) light postoperatively plus subsequent lock-in procedures and all patients returned to clinic for follow up of study parameters at 6, 9, and 12mo. Manifest refraction, distance visual acuity, and adverse events were recorded at each visit. RESULTS: The mean cylinder before adjustment in eyes with the LAL was -0.89±0.58 D (-2.00 to 0.00 D) and -0.34±0.34 D (-1.25 to 0.00 D) after lock-in (P=1.68×10^-8). The mean cylinder in patients with the monofocal lens was -1.00±0.32 D (-1.50 to -0.50 D) at 17-21d postoperatively, which was statistically different from the LAL cylinder post lock-in (P=1.43×10^-6). UDVA in the LAL group was 20/20 or better in 79% of patients post lock-in with good stability over 12mo compared with 33% of the control patients with UDVA of 20/20 or better.CONCLUSION: These results demonstrate that the LAL is more effective in achieving target refractions and improving postoperative UDVA in patients with pre-existing corneal astigmatism than a standard monofocal lens.
基金Supported in part by a research grant(BES-0209343) from the U.S.National Science Foundation
文摘A novel electrode design for the in situ generation of ozone in the reaction zone of a tubular reactor is described in this work.The ozone generator uses a porous inner electrode tube in the corona discharge assembly,and the ozone generated around the outer periphery of the porous tube diffuses into the tubular reactor and reacts with the contaminants in the fluid that is being treated.A mathematical model that includes absorption and second order reaction in the film is developed to describe ozonation kinetics of a contaminant dye in the tubular reactor.The model describes the experimental data for dye decolorization,oxidation byproducts,dissolved ozone,and ozone gas concentrations well.Model analysis indicates that the fast dye decolorization reaction occurs partly in the liquid film and partly in the bulk fluid.The model can be used in the selection of appropriate gas-liquid contactors for efficient oxidation of contaminants in effluents.
文摘Optimization of adaptive traffic signal timing is one of the most complex problems in traffic control systems. This paper presents an adaptive transit signal priority （TSP） strategy that applies the parallel genetic algorithm （PGA） to optimize adaptive traffic signal control in the presence of TSP. The method can optimize the phase plan, cycle length, and green splits at isolated intersections with consideration for the performance of both the transit and the general vehicles. A VISSIM （VISual SIMulation） simulation testbed was developed to evaluate the performance of the proposed PGA-based adaptive traffic signal control with TSP. The simulation results show that the PGA-based optimizer for adaptive TSP outperformed the fully actuated NEMA control in all test cases. The results also show that the PGA-based optimizer can produce TSP timing plans that benefit the transit vehicles while minimizing the impact of TSP on the general vehicles.
基金E.Stauffer provided invaluable field and logistical assistance.V.Izzo,A.Curtin and numerous Earthwatch volunteers were important contributors to the dataset.E.Beever and D.Pyke kindly shared their original vegetation survey data.G.Freeman allowed us access to his property within the Pumphouse plot.A grant from Earthwatch and the Betz Chair for Environmental Science funded this research.All research was conducted under the Mojave National Preserve Scientific Research and Collecting Permit No.MOJA-2003-SCI-0068(Study No.MOJA-00116)the State of California Collecting Permit 801176-04the US Fish and Wildlife Service(10(a)1(A))Permit No.TE049000-0,following a protocol approved by the Drexel University IACUC(01059,Project No.689).
文摘Desert resource environments(e.g.microclimates,food)are tied to limited,highly localized rainfall regimes which generate microgeographic variation in the life histories of inhabitants.Typically,enhanced growth rates,reproduction and survivorship are observed in response to increased resource availability in a variety of desert plants and short-lived animals.We examined the thermal ecology and reproduction of US federally threatened Mojave desert tortoises(Gopherus agassizii),long-lived and large-bodied ectotherms,at opposite ends of a 250-m elevation-related rainfall cline within Ivanpah Valley in the eastern Mojave Desert,California,USA.Biophysical operative environments in both the upper-elevation,“Cima,”and the lower-elevation,“Pumphouse,”plots corresponded with daily and seasonal patterns of incident solar radiation.Cima received 22%more rainfall and contained greater perennial vegetative cover,which conferred 5°C-cooler daytime shaded temperatures.In a monitored average rainfall year,Cima tortoises had longer potential activity periods by up to several hours and greater ephemeral forage.Enhanced resource availability in Cima was associated with larger-bodied females producing larger eggs,while still producing the same number of eggs as Pumphouse females.However,reproductive success was lower in Cima because 90%of eggs were depredated versus 11%in Pumphouse,indicating that predatory interactions produced counter-gradient variation in reproductive success across the rainfall cline.Land-use impacts on deserts(e.g.solar energy generation)are increasing rapidly,and conservation strategies designed to protect and recover threatened desert inhabitants,such as desert tortoises,should incorporate these strong ecosystem-level responses to regional resource variation in assessments of habitat for prospective development and mitigation efforts.
基金These analyses were supported in part by the National Science Foundation(Award#SES-1444755)the Hudson River Foundation(013/15A)New York Sea Grant(R/CTP-48),and the Professional Staff Congress of the City University of New York(PSC-CUNY).
文摘Dense cities represent biogeochemical hot spots along the shoreline,concentrating fixed nitrogen that is subsequently discharged into adjacent coastal receiving waters.Thus,the ecosystem services provided by natural systems in highly urban environments can play a particularly important role in the global nitrogen cycle.In this paper,we review the recent literature on nitrogen regulation by temperate coastal ecosystems,with a focus on how the distinct physical and biogeochemical features of the urban landscape can affect the provision of this ecosystem service.We use Jamaica Bay,an ultra-urbanized coastal lagoon in the United States of America,as a demonstrative case study.Based on simple areal and tidal-based calculations,the natural systems of Jamaica Bay remove~24%of the reactive nitrogen discharged by wastewater treatment plants.However,this estimate does not represent the dynamic nature of urban nitrogen cycling represented in the recent literature and highlights key research needs and opportunities.Our review reveals that ecosystem-facilitated denitrification may be significant in even the most densely urbanized coastal landscapes,but critical uncertainties currently limit incorporation of this ecosystem service in environmental management.
