Differences In Rate Of Change Research Articles

Influence of hot plastic deformation on properties of the carbon steel

Purpose. Determination of the influence of hot plastic deformation degree on the set of carbon steel properties. Methodology. Steel with 0.6 % carbon was used for the study. The steel structure corresponded to the state after compression at 1,240 °C. Mechanical properties were determined by the tensile curve, friction stress of the ferrite crystal lattice and resistance of interphase boundary pearlite to propagation of deformation were estimated. Findings. Depending on the structural state of austenite, dispersion of pearlite colonies is accompanied by different rates of change in the properties of carbon steel. For pearlite formed from austenite after annealing, the strain hardening coefficient and maximum ductility are inversely proportional. For pearlite formed from austenite with preserved substructure after hot deformation, the strain hardening coefficient and maximum ductility are related through the proportional relationship. Originality. Preservation of the substructure of hot-deformed austenite affects propagation deformation in pearlite of the steel. Against the background of decreasing friction stress of the ferrite crystal lattice, there is an increase in resistance of ferrite-cementite boundary of the pearlite to the spread of deformation. Practical value. For carbon steels with a pearlite structures, the accelerated increase in ductility from maintaining the proportion of hot work hardening of the austenite will improve technology for manufacturing rolled products of large sections. When producing thermally strengthened rolled products, achieving a simultaneous increase in strength and plastic properties is ensured by increasing ability of metal to strain hardening.

A novel method to eliminate the symmetry dependence of fiber coils for shupe mitigation

It is a well-known fact that interferometric fiber optic gyroscopes (IFOGs) are easily distorted by thermal effects and distortion results in the degradation of the performance of these sensors. Changing the fiber coil geometry, increasing the winding symmetry, adding fiber buffer layers around the fiber coil, using different modulation methods for multifunctional integrated optic chips, and using special types of fibers, such as photonic crystal fibers, are some alternative solutions for preventing this degradation. This paper, theoretically and experimentally, investigates not only how different types of fiber coil winding methods behave under different rates of temperature change but also presents a novel method, to the best of our knowledge, to eliminate the Shupe effect, without violating the simplest IFOG scheme. This method rules out the importance of the winding symmetry epochally and the need of any extra treatment for the fiber coil to increase the thermal performance of the system. Regardless of the symmetry of the fiber coil winding, the rate error due to the Shupe effect can be reduced to about ±0.05∘/\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\pm 0.05^\\circ /$$\\end{document}h for any rate of temperature change with this new method according to the experimental results.

Evaluation of thermal comfort during showering with system-related temperature fluctuations

With the decarbonization of heating sector with temperature-sensitive heat pump, comfort must be considered. For users, comfort is a decisive criterion that can hinder the decision for a supply system using renewable energies. Instantaneous domestic hot water heater pose a particular challenge here, as load changes can easily lead to temperature fluctuations. Therefore, the following study aims to determine the perception of temperature fluctuations during showering and to classify them for an assessment procedure. For this purpose, we carried out tests with 120 persons in a controlled environment. The test subjects showered at their desired temperature and gave direct feedback on imposed temperature fluctuations. Positive and negative changes with different rates of change were examined. We reported clear individual differences in the set desired temperatures as well as in the noticed and tolerated temperature fluctuations. The average desired temperature was 38.5 °C, with a quite large variation of ±5.5 K. While 2 % of the test subjects already noticed fluctuations <0.5 K and found them uncomfortable, for others (≈40 %) deviations of 4 K were still comfortable. Therefore, the resulting evaluation was based on a proportion of dissatisfied subjects according to the procedure described by the ISO 7730. This study represents a first step towards the introduction of standardized assessment of instantaneous water heaters and the comfort criteria would allow a comparison of control quality for different applications.

Thinning and dynamics of the glacier terminus at the Pasterze Glacier (Austria), 2016–2021

As a result of global warming, glaciers worldwide recede and lose mass. Glacier ablation is influenced by surface characteristics, in particular the existence of debris cover. The evolution of glaciers may also be influenced by the existence of proglacial lakes, which are worldwide increasing in number and size. We examine the recent changes of the terminus of Pasterze Glacier by discussing the thinning and dynamics of the glacier terminus along with the changes of the glacial-proglacial transition zone between September 2016 and September 2021. By considering land cover in the interpretation, we find that glacier surface characteristics show different rates of elevation changes and surface movement. We mainly use orthophotos and digital elevation models (DEMs) resulting from airborne surveys of 12 different acquisition dates, but also draw on ablation stake measurements, lake water level data, water temperature data, as well as thermal infrared (TIR) imagery. While debris-covered ice lowered typically −5.0 m a−1 ± 4.6 m a−1 (mean ± standard deviation), debris-free ice was affected by ablation in the range of −7.0 m a−1 ± 2.7 m a−1, thus demonstrating that melt rates in similar elevations are related to surface characteristics. The elevation change rates were, in most cases, in a similar range throughout the observed periods of time. The horizontal displacement close to glacier-marginal crevasses amounted to up to ∼8 m a−1, but was mostly in the range of ∼1–4 m a−1. Considering both horizontal displacement and elevation changes, we find that clean and dirty ice surfaces show larger thickness losses and are moving faster compared to debris-covered glacier surfaces. Diurnal and seasonal fluctuations of lake water levels in the range of decimeters and lake water temperatures mostly clearly exceeding 0 °C are indicative of the potential influence of the proglacial lake on the glacier terminus. Given the decelerating and decaying behavior of the Pasterze Glacier in recent decades, we interpret the change rates of surface lowering and horizontal displacement 2016–2021 to be influenced by other factors such as the recently formed proglacial lake. This is also supported by direct ablation measurements that mostly show lesser ice melt differences compared to DEM-based surface elevation changes, suggesting that other factors such as thermally-induced melting contributed to an increased elevation difference.

Longitudinal change of plasma biomarkers with incident mild cognitive impairment or Alzheimer’s disease in a multi‐ethnic cohort

AbstractBackgroundThe utility of plasma‐based Alzheimer’s biomarkers in differentiating cognitively healthy individuals from those with Mild Cognitive Impairment (MCI) or Alzheimer’s disease (AD) has been widely investigated in cross‐sectional studies. There are fewer data on longitudinal change of these biomarkers over time, particularly in multi‐ethnic cohorts.MethodBased on a community‐based, multi‐ethnic cohort study, the Washington Heights Inwood Columbia Aging Project, we included 610 cognitively normal individuals with three plasma samples collected over a mean period of 6.7 years. We used AD biomarkers, including Aβ40, Aβ42, tau, phosphorylated tau‐181 (P‐tau181), glial fibrillary acid protein (GFAP), and neurofilament light chain (NfL), and two calculated ratio measures (Aβ42/Aβ40, P‐tau181/Aβ42). During the follow‐up, 156 individuals developed MCI, 50 developed AD, and 404 remained cognitively unimpaired. We used generalized estimating equations to examine whether those who developed MCI and AD had different rates of change in plasma biomarkers than controls. Analyses were adjusted for age, years of education, sex, race and ethnicity, and APOE ɛ4 status. Similar analyses were performed to examine whether the rate of biomarker change differed by race and ethnicity, sex, and APOE ɛ4 status.ResultThe initial mean age of individuals was 73.1 (SD = 5.6) years, 419 (69%) were women, and 25.9% carried APOE e4. Individuals self‐identified as non‐Hispanic White (28.9%), non‐Hispanic Black (25.4%), or Hispanic (45.7%). Compared to controls, individuals with incident MCI had an accelerated increase in P‐tau181 (b = 0.029, p = 0.048), NfL (b = 0.027, p = 0.010), GFAP (b = 0.029, p = 0.002), and a more rapid decrease in Aβ42/Aβ40 ratio (b = ‐0.015, p = 0.033). Individuals with incident AD also had a greater increase in NfL (b = 0.041, p = 0.027) and GFAP (b = 0.04, p = 0.006) than controls. Hispanics had a faster increase in NfL (b = 0.033, p = 0.002) and GFAP (b = 0.034, p&lt;0.001), and Black participants had a faster increase in NfL (b = 0.028, p = 0.023), compared to Whites. Neither sex nor APOE ɛ4 genotype affected rates of biomarker changes.ConclusionLongitudinal change in plasma biomarkers may have clinical utility, since incident MCI and AD are accompanied by faster increases in P‐tau181, NfL, and GFAP, and a faster decrease in Aβ42/ Aβ40 ratio. The trajectories of AD biomarker change may also vary by race and ethnicity.

Porcelaneous larger foraminiferal responses to Oligocene–Miocene global changes

Sea surface temperatures (SST) have been identified as a main controlling factor on larger benthic foraminifera (LBF) living in tropical to sub-tropical shallow-water carbonate and mixed siliciclastic‑carbonate platforms. Changes in SST, along with those in ocean acidification and nutrient content recorded in the global oceans throughout their history will not only continue but also be amplified in the future at an unprecedented rate of change possibly reaching levels found in the geological record. This study focuses on the Oligocene (mean SST 8 °C higher than present) and the Miocene (SST 5–8 °C higher than present) epochs which were characterized by a higher richness in porcelaneous LBF (pLBF) than today. A systematic re-assessment and comprehensive literature survey of stratigraphic ranges and palaeogeographic distribution in the Western Tethyan (Mediterranean) and Indo-Pacific regions are used to evaluate the impact of changes in SST, seawater pCO2 and pH on the biodiversity of the Oligocene–Miocene pLBF Alveolinella, Austrotrillina, Borelis, Bullalveolina, Flosculinella, and Praebullalveolina. Two peaks in species richness were identified during the Aquitanian and Langhian–Serravallian. These peaks occurred when SST was ∼29 °C, with pCO2 of ∼400 ppm and pH > 7.8. These values are comparable to those of today. The minima in species richness recorded in the Rupelian–early Chattian, in the Burdigalian and from the Tortonian onward can be correlated to the detrimental effects of both minimum (< 26 °C) and maximum (> 31 °C) SST thresholds. High pCO2 (> 600 ppm) values, which are limited to the Rupelian–early Chattian, are also detrimental to species richness. Seawater pH higher than 7.7 did not negatively affect species richness. These historical trends have serious implications for the future diversity of pLBFs with the increasing likely scenario of rising SST and pCO2 and lowering of pH values in the near future. These developments can potentially lead to diversity decrease and even extinction of pLBFs. However, the resilience of present-day pLBF species to rising SST and pCO2 levels is underpinned by the evolutionary histories of their fossil counterparts during climate variations, albeit at much different rates of change.

Multi-Scenario Prediction Analysis of Carbon Peak Based on STIRPAT Model-Take South-to-North Water Diversion Central Route Provinces and Cities as an Example

With the increase in energy demand, environmental issues such as carbon emissions are becoming more and more prominent. China will scale its intended nationally determined contributions by adopting more vigorous policies and measures. China aims to have CO2 emissions peak before 2030 and achieve carbon neutrality before 2060. The current challenge and priority of China’s high-quality development is to ensure a harmonious balance between the ecological environment and the economy. The South-to-North Water Diversion Project passes through Beijing, Tianjin, Henan, and Hebei, which were chosen as the study sites. The carbon emission data was from the China Carbon Emission Database 2000–2019. Decoupling modeling using statistical yearbook data from four provinces and municipalities. KMO and Bartlett’s test used SPSS 27 software. The selection of indicators was based on relevance. Analyses were performed using the extended STIRPAT model and ridge regression. Moreover, projections of carbon peaks in the study area for 2020–2035 under different rates of change were simulated by the scenario analysis method. The results show that: (1) The decoupling analysis of the four provinces and cities from 2000-2019 gradually shifts to strong decoupling; (2) Resident population, energy structure, and secondary industry as a proportion of GDP significantly impact carbon emissions; (3) From 2000–2035, Beijing and Henan experienced carbon peaks. The peak time in Beijing was 96.836 million tons in 2010. The peak time in Henan was 654.1004 million tons in 2011; (4) There was no peak in Hebei from 2000–2035.

Contrasting effects of different organic amendments on the microbial responses to extreme temperature changes

Soil organic amendments can change microbial communities, potentially impacting their resilience to environmental stresses and, consequently, their transformation of soil carbon and nitrogen. While several studies have investigated the impact of a few organic amendments on microbial resilience to stresses in the form of absolute change in environmental conditions, the potential stress effects of different rates of change have received much less attention. The rate of change in environmental properties such as temperature may induce different microbial stress responses, given the reliance of microbial defensive mechanisms on time-dependent signalling and activation processes. In this research, we explored the relevance of the rate of temperature change as a microbial stressor and evaluated the potential use of organic amendments in steering soil ecological response. We monitored the changes in microbial properties and concentrations of different carbon and nitrogen fractions to temperature change treatments of 2.5 and 30 °C/d after the application of three commonly available rural organic amendments to a podzol soil in a laboratory incubation study. Results showed significant effects of the temperature treatments on bacterial and total microbial DNA concentrations, as well as on dissolvable and insoluble carbon and nitrogen ratios regardless of the organic amendment treatment. Temperature impacts on respiration rates, priming rates and the concentration of soil hot water extractable carbon and nitrogen differed depending on the organic amendment treatment. Results demonstrated that compost-amended soils were least sensitive to the temperature treatments, while grasses and fermented grasses treatments were generally more sensitive while showing opposite responses. Our findings indicate that organic amendments might be utilized to manipulate the impact of environmental stresses on soil carbon and nitrogen concentrations, and highlight the need for future research to investigate the relevant ecological properties and mechanisms.

Agricultural trade Performance: A Case Study of Indian Oilseeds

"A country’s comparative advantage in world trade may be affected by differential rates of change in production, factor accumulation or by other countries’ increased trade integration. The study of trade balance of agriculture sector would reveal that export always outstripped import, but what is distressing for agriculture import was that one commodity accounted for large proportion in import that commodity was edible oils. The export of any commodity in large quantities do not necessarily indicate that nation is competitive in the world market. The present study is an attempt to study the growth trend, variability, and the comparative advantage of major oilseeds export from India using revealed comparative advantage, trade specification coefficient, revealed symmetric comparative advantages and revealed competitive advantage indices. Growth trend analysis for export and import values indicates that, with the exception of export quantity of oilseed nes and import quantity and value of linseed, all showed a positive trend with high inter-annual variability over the period of the study. Following the TSC analysis, the value of export exceeded the value of import for all oilseed crops except linseed, and certain years of fluctuation were observed in the case of oilseed nes over the period of the study. The analysis of competitiveness of oilseeds export showed a favourable competitive scenario except in the case of linseed where in early 2000’s India was inefficient in export and for oilseed nes competitive advantage indices showed negative values for some years revealing lack of export competitiveness."

Study on stress corrosion properties of aviation aluminum alloy friction stir welded joint at the different strain rate

Aviation aluminum alloy welded structures are subjected to stresses at different strain rates in corrosive environments such as the ocean. Studying the stress corrosion properties of aviation aluminum alloy Friction Stir Welding (FSW) structures is essential. Therefore, this paper focuses on the study of 12 mm thick 7085-T7452 high-strength aviation aluminum alloy FSW joints under different strain rates of stress corrosion properties changes and the impact of welding process parameters. The main conclusions of this thesis are as follows: For the base material (BM) and the aluminum alloy FSW joints, when the strain rate increased from 10−7 s−1 to 10−5 s−1, the stress corrosion strength increased, and the stress corrosion cracking (SCC) sensitivity index ISSRT decreases. The SCC sensitivity at the same strain rate: SS-400-120 > SS-300-60 > SS-300-120 > BM. After the Slow strain rate tensile (SSRT) test, the FSW joint fracture in the air is a transgranular ductile fracture. Meanwhile, the fracture is a ductile-brittle hybrid fracture in 3.5% NaCl solution, and the number of secondary cracks along the grain boundary increased significantly, showing obvious SCC sensitivity. The BM fracture after SSRT is ductile, showing lower SCC sensitivity.

Influence of scat ageing on the gut microbiome: how old is too old?

BackgroundThe study of the host-microbiome by the collection of non-invasive samples has the potential to become a powerful tool for conservation monitoring and surveillance of wildlife. However, multiple factors can bias the quality of data recovered from scats, particularly when field-collected samples are used given that the time of defecation is unknown. Previous studies using scats have shown that the impact of aerobic exposure on the microbial composition is species-specific, leading to different rates of change in microbial communities. However, the impact that this aging process has on the relationship between the bacterial and fungal composition has yet to be explored. In this study, we measured the effects of time post-defecation on bacterial and fungal compositions in a controlled experiment using scat samples from the endangered koala (Phascolarctos cinereus).ResultsWe found that the bacterial composition remained stable through the scat aging process, while the fungal composition did not. The absence of an increase in facultative anaerobes and the stable population of obligate anaerobic bacteria were likely due to our sampling from the inner portion of the scat. We report a cluster of fungal taxa that colonises scats after defecation which can dilute the genetic material from the autochthonous mycoflora and inhibit recovery.ConclusionWe emphasize the need to preserve the integrity of scat samples collected in the wild and combat the effects of time and provide strategies for doing so.

Temporal patterns of the burden of Alzheimer's disease and their association with Sociodemographic Index in countries with varying rates of aging 1990-2019.

To we examine the temporal patterns of the burden of Alzheimer's disease and their association with Sociodemographic Index in countries with varying rates of aging. Data were obtained from Global Burden of Diseases studies (GBD) 2019 and were used to compare countries with different rates of change in aging population from 1990 to 2019. We collected the data of the age-standardized rates per 100,000 of disability-adjusted life years (DALYs), incidence, prevalence of Alzheimer's disease and other dementias, and the age-specific population rates per 100,000. Countries with high rates of change in their aging populations had an increase in DALYs, incidence, and prevalence of Alzheimer's disease and other dementias over the last 30 years. Countries with a high rate of change in aging population had a significantly positive association among DALYs, incidence, and prevalence of Alzheimer's disease and other dementias. In contrast, countries with a medium and low rate of change in aging population had negative associations between DALYs and incidence of Alzheimer's disease and other dementias. This study highlights the significant impact of demographic changes on the burden, prevalence, and incidence of Alzheimer's disease and other dementia. The study also found that robust health care and social systems, as reflected by a higher Sociodemographic Index, can contribute to reducing the burden of Alzheimer's disease and other dementias in medium to low rates of aging populations. The findings underscore the importance of investing in health care and social systems to address the growing burden of these conditions, especially in countries with a high rate of change in the aging population.

Groundwater mapping and locally engaged water governance in a small island terrain: Case study of Karainagar island, Northern Sri Lanka

AbstractGroundwater is a vital resource under threat in island communities. Karainagar, a 22 km2island, is one of seven islands off the coast of Jaffna in Northern Sri Lanka, with its population of just about 11,000 persons, experiences seasonal water shortage, and salinity in groundwater as twin threats impacting on their lives. This paper reports on a 3‐year study (October 2019 to September 2022) to map groundwater dynamics of Karainagar island spatially and seasonally and discusses the patterns revealed in terms of community needs, policy implications, and governance ideas that could already be considered by relevant authorities and citizens jointly. Thirty‐six dug wells used for drinking, domestic, agricultural, and public purposes were selected, and water level, salinity, and pH changes recorded along with daily rainfall. This paper offers a thorough description of the geography, land use, distribution of wells, and water bodies, followed by discussion of the current status of the groundwater in Karainagar island. Year‐to‐year differences in rainfall pattern resulted in different rates of change and range in water level with a corresponding reverse pattern seen in salinity with some exceptions across the island. Cumulative rainfall required to reach full capacity of wells ranged from 652 to 892 mm over the 3 years with an average figure of 739 mm of rain. This implies that any further rainfall during early phase of the main rainy season is potential surface water for storage and runoff. Practices such as unregulated pumping and construction of tube wells are argued to be contributing to increase in salinity levels with health implications for residents. A participatory governance approach that overcomes limitations of the existing institutional approach is proposed. Its success based on broad stakeholder engagement, improved equity, and transparency when supported by adequate policies and village level aquifer monitoring will enable sustainability of groundwater resources in Karainagar.

BLEDNet: Bio-inspired lightweight neural network for edge detection

Edge detection is fundamental to advanced computer vision tasks. Although deep learning-based methods can generate excellent results, they tend to be computationally expensive. To address this issue, researchers have explored the development of lightweight CNNs. Physiological studies have shown that there are two visual pathways in the biological visual system. The second visual pathway can modulate the first visual pathway, aiding the visual cortex in extracting edges from images more quickly. The inferior temporal cortex can integrate the edge signals extracted by the visual pathways and generate edges. Inspired by this, we designed a bio-inspired lightweight edge detection CNN, which includes an Encoder and a Decoder. The Encoder consists of a bio-inspired first visual pathway network and a bio-inspired second visual pathway network. The Decoder consists of a compact receptive field enhanced network. Specifically, the bio-inspired first visual pathway network can calculate the rate of change of image pixels. Through adaptive antagonism, signals with different rates of change are mutually suppressed. Meanwhile, the bio-inspired second visual pathway network can guide the bio-inspired first visual pathway network to focus more on the salient parts of the image. In addition, the receptive field-enhanced network can perceive image features distributed along specific directions, helping the decoder generate clearer edges. Our proposed method achieves competitive results on the BSDS500 dataset with ODS=0.805 and on the NYUD-v2 dataset with ODS = 0.757, while also having lower computational costs than most existing methods. Therefore, our approach is suitable for devices with lower computing capabilities.

Longitudinal changes in Alzheimer's-related plasma biomarkers and brain amyloid.

Understanding longitudinal plasma biomarker trajectories relative to brain amyloid changes can help devise Alzheimer's progression assessment strategies. We examined the temporal order of changes in plasma amyloid-β ratio ( ), glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), and phosphorylated tau ratios ( , ) relative to 11 C-Pittsburgh compound B (PiB) positron emission tomography (PET) cortical amyloid burden (PiB-/+). Participants (n=199) were cognitively normal at index visit with a median 6.1-year follow-up. PiB groups exhibited different rates of longitudinal change in . Change in brain amyloid correlated with change in GFAP (r=0.5, 95% CI=[0.26, 0.68]). The greatest relative decline in (-1%/year) preceded brain amyloid positivity by 41 years (95% CI=[32, 53]). Plasma may begin declining decades prior to brain amyloid accumulation, whereas p-tau ratios, GFAP, and NfL increase closer in time. HIGHLIGHTS Plasma declines over time among PiB- but does not change among PiB+. Phosphorylated-tau to Aβ42 ratios increase over time among PiB+ but do not change among PiB-. Rate of change in brain amyloid is correlated with change in GFAP and neurofilament light chain. The greatest decline in may precede brain amyloid positivity by decades.

Phenological shifts and mismatch with marine productivity vary among Pacific salmon species and populations.

Global climate change is shifting the timing of life-cycle events, sometimes resulting in phenological mismatches between predators and prey. Phenological shifts and subsequent mismatches may be consistent across populations, or they could vary unpredictably across populations within the same species. For anadromous Pacific salmon (Oncorhynchus spp.), juveniles from thousands of locally adapted populations migrate from diverse freshwater habitats to the Pacific Ocean every year. Both the timing of freshwater migration and ocean arrival, relative to nearshore prey (phenological match/mismatch), can control marine survival and population dynamics. Here we examined phenological change of 66 populations across six anadromous Pacific salmon species throughout their range in western North America with the longest time series spanning 1951-2019. We show that different salmon species have different rates of phenological change but that there was substantial within-species variation that was not correlated with changing environmental conditions or geographic patterns. Moreover, outmigration phenologies have not tracked shifts in the timing of marine primary productivity, potentially increasing the frequency of future phenological mismatches. Understanding population responses to mismatches with prey are an important part of characterizing overall population-specific climate vulnerability.

Performance Analysis of a 300 MW Coal-Fired Power Unit during the Transient Processes for Peak Shaving

A simulation model based on Dymola modelling was developed to investigate the dynamic characteristics of automatic generation control (AGC) for variable-load thermal power units in this study. Specifically, a 300 MW unit from a power plant in northern China was used to verify the model’s validity in steady-state processes and to analyze the behavior of the main thermal parameters under different rates of load changes. The economic performance of the unit under different rates of load changes is also analyzed by combining the economic indexes of “two regulations” in the power grid. Results indicate that as the rate of load changes increases, boiler output, main steam temperature, reheat steam temperature, main steam pressure, and working temperatures of various equipment fluctuate more intensely. Specifically, at a rate of load reduction of 2.0% Pe MW/min, the maximum deviation of the main steam temperature can reach 7.6 °C, with the screen-type superheater experiencing the largest heat exchange. To achieve a balance between safety and economics for the unit, the rate of load raising should not exceed 1.2% Pe MW/min, and the rate of load reduction should not exceed 0.8% Pe MW/min. This paper applies the covariance index and AGC assessment index of the thermal power unit load control system to the established dynamic simulation model to supplement the AGC assessment index in the “two regulations”, and to provide a flexible and reasonable system evaluation result for field operators to refer to, so as to improve the economics of the system on the basis of safety.

Remotely sensed surface water variations during drought and deluge conditions in a Northern Great Plains terminal lake basin

Study regionNorthern Great Plains (NGP) region, North Dakota, USA Study focusUnderstanding climate change impacts on surface water dynamics of permanent and seasonal water areas under drought to deluge conditions in the Devils Lake Basin (DLB) utilizing a high-resolution global surface water dataset (GSWD). New hydrologic insightsFour phases of dry and wet conditions were experienced in the DLB during the 1990–2018 study period: wetting (1990–1999), stable (2000–2003), recent wetting (2004–2013) and recent drying (2014–2018). A substantial transition from bare land to permanent and seasonal water area is observed during the wetting period (1990–99) while during the stable period (2000–2003), changes are barely observed despite NGP-wide drought. In the recent wetting period (2004–2013), a noticeable gain of permanent water from seasonal and bare land is observed. During the recent drying period (2014–2018), a significant loss of seasonal water area to bare land occurred. The difference between the spring and summer surface water areas is high during the recent wetting period (e.g., 2009, 2011, 2013), but much lower as the DLB approaches a drought condition. The inter-annual and intra-annual water dynamics of permanent and seasonal water areas show different rates of change and varying hydrological lags to changing hydroclimatic drivers and these changes are sensitive to basin antecedent conditions.

Some considerations of measuring temperature sensitivity in thermal ecology

Some considerations of measuring temperature sensitivity in thermal ecology

Fast response of vegetation in East Asia to abrupt climatic events during the last deglaciation.

Climate changes had major impacts on the vegetation of East Asia during the last deglaciation. However, the rate and pattern of vegetation succession in response to large-scale climatic events during this interval are controversial. Here, we present well-dated decadal-resolution pollen records from annually laminated Maar Lake Xiaolongwan during the last deglaciation. The vegetation changes were rapid and near-synchronous with millennial-scale climatic events, including Greenland Stadial 2.1a (GS-2.1a), Greenland Interstadial 1 (GI-1), Greenland Stadial 1 (GS-1), and the early Holocene (EH). The vegetation responded in different ways to the different rates of climate change. Vegetation change was gradual [∼1 thousand years (kyr) response time] during the transition between GS-2.1a and GI-1, but it was faster (∼0.4 kyr response time) during the transitions between GI-1, GS-1, and the EH, resulting in different patterns of vegetation succession. Additionally, the amplitude and pattern of vegetation changes resembled those in the records of regional climate change based on long-chain n-alkanes δ13C and stalagmite δ18O, as well as in the mid-latitude Northern Hemisphere temperature record and the Greenland ice core δ18O record. Therefore, the rate and pattern of vegetation succession in the Changbai Mountain of Northeast Asia during the last deglaciation were sensitive to the characteristics of changes in the regional hydrothermal conditions and mid-latitude Northern Hemisphere temperature, which were linked to both high- and low-latitude atmospheric-oceanic dynamics. Overall, our findings reveal a close relationship between ecosystem succession and hydrothermal changes during these millennial-scale climatic events in East Asia during the last deglaciation.