Bias Region Research Articles

A systematic review of local to regional yield forecasting approaches and frequently used data resources

Abstract Forecasting crop yields, or providing an expectation of ex-ante harvest amounts, is highly relevant to the whole agricultural production chain. Farmers can adapt their management, traders or insurers their pricing schemes, suppliers their stocks, logistic companies their routes, national authorities their food balance sheets to guide import or export and, finally, international aid organizations can mobilize reliefs. Evidence has grown in the literature that such forecasts with a meaningful lead time are possible on various geographic scales and for a broad range of crops. Here, we present a systematic review of the methods applied in end-of-season yield forecasting and three frequently used data sources: weather data, satellite data and crop masks. Our literature database comprises 362 studies (2004–2019) which were evaluated regarding methods, crops, regions, data sources, lead time and performance. Moreover, we present 24 sources of real-time and predictive weather data, 21 sources of remote sensing data and 16 crop masks. Yield forecasting in our literature sample has been performed for 44 crops in 71 countries, also including many non-staple crops, but with an apparent bias in regions and crops. Forecasting performance depends on various factors, including crop, region, method, lead time to harvest and input diversity. Our systematic review supports a broader application of locally successful approaches at larger scales by providing a comprehensive, accessible compendium of necessary information for yield forecasting. We discuss improvement potentials with respect to methodological approaches and available data sources. We additionally suggest standardization procedures for future forecasting studies and encourage studying additional crops and geographic regions. Implications of forecasts for different target groups on different scales and the adaptation towards climate change are also discussed.

Geography, opportunity and bridgeheads facilitate termite invasions to the United States

With the ever-increasing rate of globalization, port of entry data can be an important source of information for the introduction and spread of invasive species on a worldwide scale. Using a comprehensive dataset spanning records from 1923 to 2017, termite interceptions at US ports of entry were analyzed. We identified 906 non-native interceptions originating from outside the US, including four families, 32 genera and 75 different termite species. Non-native termites originated from 88 different countries and were intercepted in 29 different states. There was a strong regional bias, with termite-rich areas closest to the US—Central America, South America and the Caribbean—the greatest exporters of termite species to the US. Among the 75 non-native termites intercepted, 12 had already become established outside of their native range, with eight appearing to utilize bridgeheads to expand their global distribution. Additionally, the establishment probability of a species was positively influenced by the number of interceptions, as three of the most common non-native species intercepted at ports of entry are currently established within the US—Nasutitermes corniger, Cryptotermes brevis and Coptotermes formosanus. Our results reveal important insights into the global dispersal of invasive termites and contribute further evidence towards the importance of trade, increased propagule pressure and the bridgehead effect as drivers of global invasion rates.

Diagnosing Mixing Properties in Model Simulations for CH4 in the Stratosphere

AbstractIsentropic mixing properties in the stratosphere modeled by the forward calculation of an inverse model (TM5‐4DVAR) are evaluated against Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and Microwave Limb Sounder (MLS) observations. The isentropic mixing processes are separated into large‐scale stirring described by the “equivalent length” and small‐scale diffusion described by the diffusivity. Compared to the measurements, we find that the modeled stirring is not strong enough and that the small‐scale diffusivity is too large. TM5‐4DVAR produces excessive mixing‐induced poleward flux for stratospheric CH4. The flux convergence presents negative biases in the tropics and positive biases in the polar regions. The biases cannot be reduced by improving the horizontal resolution only. Modeled isentropic mixing depends on the horizontal as well as the vertical resolution of the model. An increase in vertical resolution reduces numerical diffusion of the model in the vertical. The decreased vertical diffusion leads to reduction in the modeled isentropic diffusivity. Biases in modeled total column‐averaged mixing ratios of CH4 are significant for both models with a coarse vertical resolution of 4° × 6° × 25 (and 2° × 3° × 25, 1° × 1° × 25) and an improved one of 1° × 1° × 40. They are estimated to be 7–14 and 3–7 ppb in the winter extratropics under the assumption that isentropic mixing is dominant over vertical transport on a time scale of 3 days. Correspondingly, resulted biases in inverted CH4 surface emissions are estimated to be 0.5–1 and 0.2–0.5 mg/m2/hr, respectively, in the extratropics.

An Overview of CMIP5 and CMIP6 Simulated Cloud Ice, Radiation Fields, Surface Wind Stress, Sea Surface Temperatures, and Precipitation Over Tropical and Subtropical Oceans

AbstractThe potential links between ice water path (IWP), radiation, circulation, sea surface temperature (SST), and precipitation over the Pacific and Atlantic Oceans resulting from the falling ice radiative effects (FIREs) are examined from Coupled Model Intercomparison Project phase 5 (CMIP5) and phase 6 (CMIP6) historical simulations. The latter is divided into two subsets with (SON6) and without FIREs (NOS6) in CMIP6. Improvement in nonfalling cloud ice (~20 g m−2) is noticeable over convective regions in CMIP6 relative to CMIP5. The inclusion of FIREs in SON6 subset may contribute to reduce biases of overestimated outgoing longwave radiation and downward surface shortwave and underestimated reflected shortwave at the top of the atmosphere (TOA) by magnitudes of ~8 W m−2 over convective regions against CERES, compared to NOS6 subset. The reduced biases in radiative fluxes in convective regions stabilize the atmosphere and lead to circulation, SST, cloud, and precipitation changes over the trade wind regions, as seen from improved radiative fluxes (~15 W m−2), surface wind stress biases, SST (~0.8 K), and precipitation (1 mm day−1) biases. The significant improvement from NOS6 to SON6 leads to improved multimodel means for CMIP6 relative to CMIP5 for radiation fields over the trade wind regions but the degradation over convective zones is attributed to NOS6 subset. The results suggest that other sources of uncertainty and deficiencies in climate models may play significant roles for reducing discrepancies although FIREs, via radiation‐circulation coupling, may be one of the factors that help to reduce regional biases.

Numerical analysis of temperature and current distributions in large-size intrinsic Josephson junctions with self-heating

In this study, we focused on temperature and current distributions in voltage-state large-size intrinsic Josephson junction (IJJ) mesas with a self-heating effect. Because it is difficult to experimentally obtain temperature and current distributions in IJJ mesas, we numerically computed these distributions by solving non-linear diffusion and temperature dependence circuit equations. The local temperature in the mesa exceeded the critical temperature, and a normal-state appeared in the high bias region. Non-uniform temperature and current density distributions were obtained for each bias point of the current–voltage (I–V) characteristics. Normalized c-axis current distributions decreased with an increase in the bias current in the high bias regions. These results were explained using temperature dependent c-axis resistivity.

Development Zone Establishment, Regional Bias and Enterprise Green Innovation

Green innovation is an important focus for promoting the construction of ecological civilization and green development. As China’s most typical industrial agglomeration zone, whether development zones can promote park enterprises to carry out green technology innovation is an important topic that needs to be studied urgently. Based on the combination of Chinese industrial enterprise data and patent data, this paper focuses on the impact of development zone establishment on corporate green innovation through building a multi-period DID model, and combined with the regional bias characteristics of development zone policies, it discusses the difference of the impact of development zone establishment on the green innovation of enterprises in the eastern region and the central and western regions and the logical mechanism behind it. The study finds that the establishment of development zones promotes the green innovation of enterprises as a whole, which not only helps to promote the application of green utility model with lower patent value, but also helps to promote the application of green invention with more patent value. From the results of dynamic effects, the long-term incentive effect of development zone establishment on enterprise green innovation is greater than the short-term incentive effect. After the 2003 rectification of China’s development zone policies, there has been a clear central and western bias, but this regional bias may undermine economic sustainability. As a result, the green innovation incentive effect of development zone establishment on enterprises in the eastern region is significantly higher than that on enterprises in the central and western regions. Compared with the central and western regions, the establishment of development zones may more closely match the location characteristics of the eastern region and the external environment. In the long run, the establishment of development zones has significantly enhanced the incentive effect of green technology innovation for enterprises in the eastern region, while the incentive for green innovation for enterprises in the central and western regions is still insufficient, and has not achieved the expected policy guidance effect. The study also finds that the regional heterogeneity of the green innovation incentive effect in development zones may mainly come from the differences in market environment, intellectual property protection, local competition, openness to the outside world, and foreign direct investment between different regions. The establishment of development zones must be consistent with the local economy. Only by adapting the characteristics to the external environment can we better play the role of green innovation and environmental governance. This research not only expands and deepens the relevant research on development zone policies from the perspective of regional bias, but also helps to provide micro level evidence and new test standards for the evaluation on the effect of the implementation of development zone establishment policies from the new perspective of enterprise green innovation. At the same time, the conclusions of this paper can provide new policy insights for achieving a win-win situation of industrial agglomeration and ecological environment, and promoting the implementation of green development strategies.

Crack-Assisted Charge Injection into Solvent-Free Liquid Organic Semiconductors via Local Electric Field Enhancement.

Non-volatile liquid organic semiconducting materials have received much attention as emerging functional materials for organic electronic and optoelectronic devices due to their remarkable advantages. However, charge injection and transport processes are significantly impeded at interfaces between electrodes and liquid organic semiconductors, resulting in overall lower performance compared to conventional solid-state electronic devices. Here we successfully demonstrate efficient charge injection into solvent-free liquid organic semiconductors via cracked metal structures with a large number of edges leading to local electric field enhancement. For this work, thin metal films on deformable polymer substrates were mechanically stretched to generate cracks on the metal surfaces in a controlled manner, and charge injection properties into a typical non-volatile liquid organic semiconducting material, (9-2-ethylhexyl)carbazole (EHCz), were investigated in low bias region (i.e., ohmic current region). It was found that the cracked structures significantly increased the current density at a fixed external bias voltage via the local electric field enhancement, which was strongly supported by field intensity calculation using COMSOL Multiphysics software. We anticipate that these results will significantly contribute to the development and further refinement of various organic electronic and optoelectronic devices based on non-volatile liquid organic semiconducting materials.

Design of energy-conservation and emission-reduction plans of China’s industry: Evidence from three typical industries

It is important to estimate the energy-conservation and emission-reduction potentials accurately and design practicable paths to ensure the achievement of the emission reduction target set at the “Paris Climate Conference”. Selecting the petroleum and gas extraction industry, the construction industry, and the transportation industry, which are the greatest energy consumers and carbon emitters in China, this study estimates their energy-conservation and emission-reduction potentials of 2018–2025 and designs the implementation paths. The results show that: (1) under the short-term energy rebound effect, the cumulative energy-conservations of 2018–2025 of the three industriesare17.55%, 18.29%, and 13.46%, respectively; the cumulative emission-reductions are 18.21%, 14.85%, and 16.98%, respectively. Under the long-term rebound effect, the cumulative energy-conservations are 21.3%, 22.39%, and 18.54%, respectively; the cumulative emission-reductions are 19.76%, 18.1%, and 23.75%, respectively. Moreover, the effect of the short-term energy rebound effect is greater than the long-term rebound effect. (2) There are three paths for energy-conservation and emission-reduction: the “unilateral breakthrough”, the “promotion of advantages and compensate for disadvantages”, and the “leap forward” paths. (3) When formulating the energy-conservation and emission-reduction policies, for industries of resource-intensive, factor market distortion, governments’ administrative orders and intensive production should be focused on; for industries of labor-intensive, energy efficiency, energy structure, carbon tax and the upgrade of industry structure should be focused on; for industries of capital-intensive, regional investment bias, the construction of carbon trading system and clean production should be focused on. Our results can provide guidance for the formulation of energy-conservation and emissions-reduction objectives and policies for China’s industry.

Gate structure dependent normally-off AlGaN/GaN heterostructure field-effect transistors with p-GaN cap layer

In this study, the influences of a p-GaN gate structure on normally-off AlGaN/GaN heterostructure field-effect transistors were evaluated. It is demonstrated that a metal-insulator-semiconductor (MIS) gate structure can effectively suppress the gate leakage current and shift the threshold voltage positively, as compared with the Schottky and ohmic gate structures. To further improve the device performance, a novel gate-first MIS gate structure was proposed by combining the self-alignment gate and low-temperature ohmic. Good ohmic contact with a contact resistance of 1.45 Ω mm was achieved after annealing at 500 °C. For the self-aligned gate structure, a threshold voltage of 2.5 V, gate swing of 16 V, and drain current density of 50 mA mm−1 were observed. Besides, the gate leakage current was reduced to a very low level in both positive and negative bias regions.

Integrative structural, functional, and transcriptomic analyses of sex-biased brain organization in humans.

Humans display reproducible sex differences in cognition and behavior, which may partly reflect intrinsic sex differences in regional brain organization. However, the consistency, causes and consequences of sex differences in the human brain are poorly characterized and hotly debated. In contrast, recent studies in mice-a major model organism for studying neurobiological sex differences-have established: 1) highly consistent sex biases in regional gray matter volume (GMV) involving the cortex and classical subcortical foci, 2) a preponderance of regional GMV sex differences in brain circuits for social and reproductive behavior, and 3) a spatial coupling between regional GMV sex biases and brain expression of sex chromosome genes in adulthood. Here, we directly test translatability of rodent findings to humans. First, using two independent structural-neuroimaging datasets (n > 2,000), we find that the spatial map of sex-biased GMV in humans is highly reproducible (r > 0.8 within and across cohorts). Relative GMV is female biased in prefrontal and superior parietal cortices, and male biased in ventral occipitotemporal, and distributed subcortical regions. Second, through systematic comparison with functional neuroimaging meta-analyses, we establish a statistically significant concentration of human GMV sex differences within brain regions that subserve face processing. Finally, by imaging-transcriptomic analyses, we show that GMV sex differences in human adulthood are specifically and significantly coupled to regional expression of sex-chromosome (vs. autosomal) genes and enriched for distinct cell-type signatures. These findings establish conserved aspects of sex-biased brain development in humans and mice, and shed light on the consistency, candidate causes, and potential functional corollaries of sex-biased brain anatomy in humans.

Decoupling Strategy for Enhanced Syngas Generation from Photoelectrochemical CO2 Reduction.

SummaryPhotoelectrochemical CO2 reduction into syngas (a mixture of CO and H2) provides a promising route to mitigate greenhouse gas emissions and store intermittent solar energy into value-added chemicals. Design of photoelectrode with high energy conversion efficiency and controllable syngas composition is of central importance but remains challenging. Herein, we report a decoupling strategy using dual cocatalysts to tackle the challenge based on joint computational and experimental investigations. Density functional theory calculations indicate the optimization of syngas generation using a combination of fundamentally distinctive catalytic sites. Experimentally, by integrating spatially separated dual cocatalysts of a CO-generating catalyst and a H2-generating catalyst with GaN nanowires on planar Si photocathode, we report a record high applied bias photon-to-current efficiency of 1.88% and controllable syngas products with tunable CO/H2 ratios (0–10) under one-sun illumination. Moreover, unassisted solar CO2 reduction with a solar-to-syngas efficiency of 0.63% is demonstrated in a tandem photoelectrochemical cell.

Associations of area-level deprivation with adverse obstetric and perinatal outcomes in Bavaria, Germany: Results from a cross-sectional study.

We investigated associations of area-level deprivation with obstetric and perinatal outcomes in a large population-based routine dataset. We used the data of n = 827,105 deliveries who were born in hospitals between 2009 to 2016 in Bavaria, Germany. The Bavarian Index of Multiple Deprivation (BIMD) on district level was assigned to each mother by the zip code of her residential address. We calculated odds ratios (ORs) with 95% confidence intervals (CIs) for preterm deliveries, Caesarian sections (CS), stillbirths, small for gestational age (SGA) births and low 5-minute Apgar scores by BIMD quintiles with and without adjustment for potential confounders. We observed a significantly increased risk for preterm deliveries in mothers from the most deprived compared to the least deprived districts (e.g. OR [95% CI] for highest compared to lowest deprivation quintile: 1.06 [1.03, 1.09]) in adjusted analyses. Increased deprivation was also associated with higher SGA and secondary CS rates, but with lower proportions of stillbirths, primary CS and low Apgar scores. When one large clinic with an unusually high stillbirth rate was excluded, the association of BIMD with stillbirths was attenuated and almost disappeared. We found that area-level deprivation in Bavaria was positively associated with preterm and SGA births, confirming previous studies. In contrast, the finding of an inverse association between deprivation and both stillbirth rates and low Apgar score came somewhat surprising. However, we conclude that the stillbirths finding is spurious and reflects regional bias due to a clinic which seems to specialize in termination of pregnancies.

Structural and Electrical Investigation of Porous GaAs Layers on Different Crystallographically Oriented GaAs Substrates

In this paper, electrochemical anodization was used to fabricate porous layers on n-type GaAs substrates with different orientations, i.e., (511)A, (100) and (111)B, under the same experimental conditions. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray diffraction (XRD) were used to characterize the formed porous layers, with respect to the substrate orientation. Results obtained from SEM and AFM data are evidence of the formation of GaAs nanocrystallites and reveal that pores grow along definite crystallographic directions. XRD analysis confirm the single crystalline structure of porous layers and a relative peak shift as compared to GaAs, indicating a change in the lattice constant due to strain effects. The photoluminescence spectra of the porous layers showed red PL bands attributed to quantum confinement effects in GaAs nanocrystallites. The investigated current–voltage (I–V) in the forward bias region demonstrates that the transport mechanism in the Au/porous-GaAs/GaAs structures was governed by space-charge-limited current (SCLC). In fact, non-saturating behavior was observed in the reverse bias I–V characteristics due to both the effective barrier height dependence on the electric field and the thermionic field emission.

북한 비공식금융 실태조사 및 분석·평가 (Study of Informal Finance in North Korea, with Analysis and Evaluation)

Korean Abstract: 본고는 북한이탈주민에 대한 설문조사를 통해 북한 비공식금융의 실태를 파악하는 한편 타국과의 비교를 통해 그 발전 정도를 평가한 것이다. 북한이탈주민에 대한 조사결과 상거래신용, 금전대차, 계(契) 등이 대표적인 비공식금융 활동으로 파악되었으며, 이 가운데 한 가지라도 경험한 북한 주민은 27.8%로 이에 대한 경험이 아직 부족한 것으로 나타났다. 아울러 북한 주민은 그 규모 면에서 현금보관액, 상거래신용, 금전대차, 계의 순으로 비공식금융 자산을 보유하고 있었다. 주민들의 비공식금융 유형별 특징을 보면, 상인들 간에는 상거래 신용이 주된 금융수단으로 활용되고 있었으며, 금전대차는 주로 지인들 간에 담보보다는 신용에 기반하여 거래되고 있었다. 금전대차의 목적은 장사 목적이 주를 이루었고 산업생산 목적은 매우 낮게 나타났으며, 이자부 거래의 평균금리는 월 13.1%로 조사되었다. 북한의 비공식금융의 규모는 페레스트로이카 초기(1986년)의 구소련보다는 큰 수준이었으나, 중국의 경제개발 본격화 시기(2001년)나 일부 개발도상국(페루, 베트남)의 1990년대 후반 시기에 비해 작은 수준으로 평가된다. 또한 비공식 금융거래의 목적은 상거래활동 지원이 대부분이고 생산자금 비중은 매우 낮아 생산활동의 활성화에는 큰 도움이 되지 못하고 있는 것으로 나타났다. 아울러 북한의 금융중개의 주체는 대출중개인 또는 계(契)의 수준에 머물러 비공식 금융기업(비공식 저축·대부기관)으로까지는 발전하지 못한 것으로 판단된다. 본고는 비공식금융 활동을 정량적으로 파악하고 분석했다는 점에서는 진일보한 측면이 있으나 북한이탈주민에 대한 설문조사가 갖는 적은 표본 수, 지역적 편향, 회고적 조사로 인한 정확성 제한 등의 문제를 여전히 극복하지 못한 한계가 있어 해석에 유의할 필요가 있다. English Abstract: This study aims to grasp the current state of informal finance in North Korea through a questionnaire survey of North Korean defectors, and to evaluate the degree of development through comparison with other countries. The results of the survey of North Korean defectors show that trade credit, lending by individual money lenders, rotating credit & savings association were the major informal financial activities, while 27.8% of defectors have experienced at least one of these activities, showing that North Koreans still lack sufficient experience in them. In addition, North Koreans possessed informal financial assets through the following means, in the order of largest to smallest: cash holdings, trade credit, lending by individual money lenders, rotating credit & savings association. Looking at the characteristics of residents' informal financing types, trade credit was used as the main financial means among merchants, and individual money lenders issued loans mostly to acquaintances based on credit rather than collateral. The purpose of the lending by individual money lenders was mainly for distribution businesses, while lending for industrial production was rare; the average interest rate of interest-bearing transactions was 13.1% per month. North Korea's informal financing was larger than that of the former Soviet Union in the early days of perestroika (1986), but relatively small compared to China in the early days of full-scale economic development (2001) or some developing countries (Peru, Vietnam) in the late 1990s. It was also found that most informal financial transactions were to support commercial activities, while only a small proportion was used for production, meaning that informal financial transactions were not able to play a major role in vitalizing production. In addition, North Korea's financial intermediaries appear to have remained at the level of loan brokers or rotating credit & savings association and have failed to develop into informal financial companies(informal savings & loan institutions). Although this paper represents a step forward in that it quantitatively identifies and analyzes informal financial activities, readers should be aware that it still fails to overcome problems such as the small number of samples, regional bias, and accuracy limitations inherent in retrospective surveys of North Korean defectors.

Improving Current ON/OFF Ratio and Subthreshold Swing of Schottky- Gate AlGaN/GaN HEMTs by Postmetallization Annealing

Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -passivated Schottky-gate AlGaN/GaN high electron mobility transistors (HEMTs) with improved subthreshold swing (SS) and drain current ON/OFF ratio by postmetallization annealing (PMA) at 500 °C in N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ambient are reported. With the PMA, the gate leakage current in the reverse biased region and the OFF-state drain current are reduced by more than three orders of magnitude, leading to a low SS of 84.75 mV/dec and a high drain current ON/OFF ratio of 2.1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> . Through temperature-dependent current-voltage measurements on dual-Schottky-gate structures and capacitance-voltage measurements on Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /AlGaN/GaN metal-insulator-semiconductor (MIS) HEMT capacitors, it is identified that the PMA greatly suppresses both the Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /AlGaN interface leakage current and the reverse gate leakage current by eliminating Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /AlGaN interface trap states with 0.34 eV trap state energy and changing the dominant mechanism of reverse gate leakage conduction from trap-assisted tunneling to Fowler-Nordheim tunneling, respectively. Overall, this work reports on the effectiveness of PMA in improving the performance of Schottky-gate AlGaN/GaN HEMTs and the underlying improving mechanisms.

Evaluation of the CMIP6 multi-model ensemble for climate extreme indices

This study evaluates global climate models participating in the Coupled Model Intercomparison Project phase 6 (CMIP6) for their performance in simulating the climate extreme indices defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). We compare global climatology patterns of the indices simulated by the CMIP6 models with those from HadEX3 and four reanalysis datasets and the CMIP5 multi-model ensemble using root-mean-square errors for the 1981–2000 period. Regional evaluations are conducted for 41 sub-regions, defined for the Intergovernmental Panel on Climate Change Sixth Assessment Report. In particular, regional mean biases are analyzed for the 20-year return values (20RV) of the warmest day and coldest night temperatures (TXx and TNn) and annual maximum of daily precipitation (RX1day) using a Generalized Extreme Value (GEV) analysis. Results show that the CMIP6 models generally capture the observed global and regional patterns of temperature extremes with limited improvements compared to the CMIP5 models. Systematic biases like a cold bias in cold extremes over high-latitude regions remain even in stronger amplitudes. The CMIP6 model skills for the precipitation intensity and frequency indices are also largely comparable to those of CMIP5 models, but precipitation intensity simulations are found to be improved with reduced dry biases. The GEV analysis results indicate that the regional biases in 20RV of temperature extremes are dominated by GEV location parameter (related to mean intensity) with relatively small contribution from GEV scale/shape parameters (related to interannual variability). CMIP6-simulated 20RV of RX1day is characterized by dry biases over the tropics and subtropical rain band areas, as in the CMIP5 models, for which biases in both GEV location and scale/shape parameters are important.

Tuning electronic transport properties of wide antimonene nanoribbon via edge hydrogenation and oxidation

In this paper, we study the electronic structures and electronic transport properties of wide buckled and puckered antimonene nanoribbions (SbNRs) via edge hydrogenation and oxidation by using a first principle method. The calculated results show that the edge passivations play an important role in the band structures of wide buckled and puckered SbNRs. The current-voltage characteristics of buckled and puckered SbNRs consistent with their band structures. The currents of buckled and puckered SbNR devices via edge hydrogenation are nearly zero at low bias region, but the edge oxidation can enlarge the device’s conductance obviously. More importantly, the tunable negative differential resistance behavior can be found in the buckled and puckered SbNR devices via edge oxidation. Our researches are of great significance for the subsequent application of SbNR devices.

A SYSTEMATIC STUDY ON THE DIELECTRIC RELAXATION, ELECTRIC MODULUS AND ELECTRICAL CONDUCTIVITY OF Al/Cu:TiO2∕n-Si (MOS) STRUCTURES/CAPACITORS

The various levels (5%, 10% and 15%) of Cu-doped TiO2 thin films were grown on the [Formula: see text]-type silicon (Si) wafer by spin coating technique to obtain Al/(Cu:TiO[Formula: see text]/[Formula: see text]-Si (MOS) capacitors. Both the real and imaginary components of complex dielectric ([Formula: see text], complex electric modulus ([Formula: see text], loss tangent (tan [Formula: see text] and alternating electrical conductivity ([Formula: see text] of the obtained Al/(Cu:TiO[Formula: see text]-Si (MOS) capacitors were studied by taking into account the effects of Cu-doping levels into TiO2 viaimpedance spectroscopy method (ISM) in the wide range voltage ([Formula: see text][Formula: see text]V) and frequency (10[Formula: see text]kHz–1[Formula: see text]MHz). All the obtained dielectric parameters were obtained as strongly dependent on frequency, voltage and Cu doping level. The observed anomalous peak in the forward bias region both in the real and imaginary components of [Formula: see text], tan [Formula: see text], complex electric modulus ([Formula: see text] and [Formula: see text] were attributed to the Cu:TiO2 interlay er, series resistance ([Formula: see text], surface states ([Formula: see text], interfacial/surface and dipole polarizations. The higher values of [Formula: see text] at low and intermediate frequencies implied that [Formula: see text] have enough time to follow external ac signal, and also dipoles respond to the applied field to reorient themselves. Consequently, the fabricated Al/(Cu:TiO[Formula: see text]-Si can be successfully used as MOS capacitor or MOS-field-effect transistor (MOSFET) in the industrial applications in near future.

Local-Mean Preserving Post-Processing Step for Non-Negativity Enforcement in PET Imaging: Application to 90Y-PET

In a low-statistics PET imaging context, the positive bias in regions of low activity is a burning issue. To overcome this problem, algorithms without the built-in non-negativity constraint may be used. They allow negative voxels in the image to reduce, or even to cancel the bias. However, such algorithms increase the variance and are difficult to interpret since the resulting images contain negative activities, which do not hold a physical meaning when dealing with radioactive concentration. In this paper, a post-processing approach is proposed to remove these negative values while preserving the local mean activities. Its original idea is to transfer the value of each voxel with negative activity to its direct neighbors under the constraint of preserving the local means of the image. In that respect, the proposed approach is formalized as a linear programming problem with a specific symmetric structure, which makes it solvable in a very efficient way by a dual-simplex-like iterative algorithm. The relevance of the proposed approach is discussed on simulated and on experimental data. Acquired data from an yttrium-90 phantom show that on images produced by a non-constrained algorithm, a much lower variance in the cold area is obtained after the post-processing step, at the price of a slightly increased bias. More specifically, when compared with the classical OSEM algorithm, images are improved, both in terms of bias and of variance.

What Motivates Behavior Change? Analyzing User Intentions to Adopt Clean Technologies in Low-Resource Settings Using the Theory of Planned Behavior

Understanding and integrating the user’s decision-making process into product design and distribution strategies is likely to lead to higher adoption rates and ultimately increased impacts, particularly for those products that require a change in habit or behavior such as clean energy technologies. This study applies the Theory of Planned Behavior (TPB) in design for global development, where understanding the tendency to adopt beneficial technologies based on parsimonious approaches is critical to programmatic impact. To investigate robustness and applicability of behavioral models in a data scarce setting, this study applies TPB to the adoption of biomass cookstoves in a sample size of two remote communities in Honduras and Uganda before and after a trial period. Using multiple ordinal logistic regressions, the intention to adopt the technology was modeled. Results quantify the influence of these factors on households’ intentions to cook their main meals with improved cookstoves. For example, the intention of participants with slightly stronger beliefs regarding the importance of reducing smoke emissions was 3.3 times higher than average to cook more main meals with clean cookstoves. The quantitative method of this study enables technology designers to design and develop clean technologies that better suit user behavior, needs, and priorities. In addition, the data driven approach of this study provides insights for policy makers to design policies such as subsidies, information campaigns, and supply chains that reflect behavioral attributes for culturally tailored clean technology adoption initiatives. Furthermore, this work discusses potential sources of bias and statistical challenges in data-scarce regions, and outlines methods to address them.