bluuebunny/crossref_metadata_2025 huggingface dataset:
Diffusional growth of cloud droplets in homogeneous isotropic turbulence: DNS, scaled-up DNS, and stochastic model
Authors: Thomas Lois , Grabowski Wojciech W. , Kumar Bipin
Published: February 2020

Abstract. This paper presents a novel methodology to use the Direct Numerical Simulation (DNS) to study the impact of isotropic homogeneous turbulence on the condensational growth of cloud droplets. As shown by previous DNS studies, the impact of turbulence increases with the computational domain size, that is, with the Reynolds number, because larger eddies generate higher and longer-lasting supersaturation fluctuations that affect growth of individual cloud droplets. The traditional DNS can only simulate a limited range of scales because of the excessive computational cost that comes from resolving all scales involved, that is, from large scales at which the turbulent kinetic energy (TKE) is introduced down to the Kolmogorov microscale, and from following every single droplet. The novel approach is referred to as the scaled-up DNS. The scaling-up is done in two parts, first by increasing both the computational domain and the Kolmogorov microscale, and second by using super-droplets instead of real droplets. To ensure proper dissipation of TKE and scalar variance at small scales, molecular transport coefficients are appropriately scaled-up with the grid length. For the scaled-up domains, say, meters and tens of meters, one needs to follow billions of real droplets. This is not computationally feasible, and so-called super-droplets are applied in scaled-up DNS simulations. Each super-droplet represents an ensemble of identical real droplets, and the number of real droplets represented by a super-droplet is referred to as the multiplicity attribute. After simple tests showing validity of the methodology, scaled-up DNS simulations are conducted for five domains, the largest of 643 m3 volume using a DNS of 2563 grid points and various multiplicities. All simulations are carried out with vanishing mean vertical velocity and with no mean supersaturation, similarly to past DNS studies. As expected, the supersaturation fluctuations as well as the spread in droplet size distribution increase with the domain size, with the mean droplet radius variance increasing in time t as t1/2 as identified in previous DNS studies. Scaled-up simulations with different multiplicities document numerical convergence of the scaled- up solutions. Finally, we compare the scaled-up DNS results with a simple stochastic model that calculates supersaturation fluctuations based on the vertical velocity fluctuations updated using the Langevin equation. Overall, the results document similar scaling as in previous small-domain DNS simulations and support the notion that the stochastic subgrid-scale model is a valuable tool for the multi-scale simulation of droplet spectral evolution applying large-eddy simulation model.
Lagrangian Gravity Wave spectra in the lower stratosphere of current (re)analyses
Authors: Podglajen Aurélien , Hertzog Albert , Plougonven Riwal , Legras Bernard
Published: February 2020

Abstract. Due to their increasing spatial resolution, numerical weather prediction (NWP) models and the associated analyses resolve a growing fraction of the gravity wave (GW) spectrum. However, it is unclear how well this resolved part of the spectrum actually compares to the actual atmospheric variability. In particular, the Lagrangian variability, relevant, e.g., to atmospheric dispersion and to microphysical modeling in the Upper Troposphere-Lower Stratosphere (UTLS), has not yet been documented in recent products. To address this shortcoming, this paper presents an assessment of the GW spectrum as a function of the intrinsic (air parcel following) frequency in recent (re)analyses (ERA-interim, ERA5, the ECMWF operational analysis, MERRA-2 and JRA-55). Long-duration, quasi-Lagrangian balloon observations in the equatorial and Antarctic lower stratosphere are used as a reference for the atmospheric spectrum and compared to synthetic balloon observations along trajectories calculated using the wind and temperature fields of the reanalyses. Overall, the reanalyses represent realistic features of the spectrum, notably the spectral gap between planetary and gravity waves and a peak in horizontal kinetic energy associated with inertial waves near f in the polar region. In the tropics, they represent the slope of the spectrum at low frequency. However, the variability is generally underestimated, even in the low-frequency portion of the spectrum. In particular, the near-inertial peak, although present in the reanalyses, has a much reduced magnitude compared to balloon observations. We compare the variability of temperature, momentum flux and vertical wind speed, which are related to low, mid and high frequency waves, respectively. The distributions (PDFs) have similar shapes, but show increasing disagreement with increasing intrinsic frequency. Since at those altitudes they are mainly caused by gravity waves, we also compare the geographic distribution of vertical wind fluctuations in the different products, which emphasizes the increase of both GW variance and intermittency with horizontal resolution. Finally, we quantify the fraction of resolved variability and its dependency on model resolution for the different variables. In all (re)analyses products, a significant part of the variability is still missing and should hence be parameterized, in particular at high intrinsic frequency. Among the two polar balloon datasets used, one was broadcast on the global telecommunication system for assimilation in analyses while the other is made of independent observations (unassimilated in the reanalyses). Comparing the Lagrangian spectra between the two campaigns shows that they are largely influenced by balloon data assimilation, which especially enhances the variance at low frequency.
Nighttime O(1D) distributions in the mesopause region derived from SABER data
Authors: Kulikov Mikhail Yu. , Belikovich Mikhail V.
Published: February 2020

Abstract. In this study, the new source of O(1D) in the mesopause region due to the process OH(ν ≥ 5) + O(3P)  → OH(0 ≤ ν’ ≤ ν-5) + O(1D) is applied to SABER data to estimate the nighttime O(1D) distributions for the years 2003–2005. It is found that O(1D) evolutions in these years are very similar to each other. Depending on the month, monthly averaged O(1D) distributions demonstrate from 2 to 4 maxima with the values up to 340 cm−3 which are localized in height (at ~ 92–96 km) and latitude (at ~ 20–40° S,N and ~ 60–80° S,N). Annually averaged distributions in 2003–2005 have a one weak maximum at ~ 93 km and ~ 65° S with the values of 150–160 cm−3 and 3 pronounced maxima (with the values up to 230 cm−3) at ~ 95 km and ~ 35° S, at ~ 94 km and ~ 40° N, at ~ 93 km and ~ 65–75° N correspondingly. In general, there is slightly more O(1D) in the northern hemisphere than in the southern hemisphere. The obtained results are useful data set for subsequent estimation of nighttime O(1D) influence on chemistry of the mesopause region.
Development of a revised IHA method for the cumulative impacts of cascade reservoirs on flow regime
Authors: Zhou Xingyu , Huang Xiaorong , Zhao Hongbin , Ma Kai
Published: February 2020

Abstract. The impacts of reservoirs, especially multiple reservoirs, on the flow regimes and ecosystems of rivers have received increasing attention. The most widely used metrics to quantify the characteristics of flow regime alterations are the indicators of hydrologic alteration (IHA) which include 33 parameters. Due to the difference in the degree of alteration and the intercorrelation among IHA parameters, the comprehensive evaluation method that assigns the same weight to each indicator is obviously inadequate. A revised IHA method is proposed by utilizing the projection pursuit (PP) and real-coded accelerated genetic algorithm (RAGA). Data reliability is analysed by using the length of record (LOR) method. The projection values reflecting the comprehensive characteristics of the evaluation parameters are calculated. Based on these methods, a scientific and reliable evaluation of the cumulative impacts of cascading reservoirs on the flow regime was made by examining the Jinsha River. The results showed that with the continuous construction of reservoirs, the alteration degrees of IHA parameters gradually increased in Groups 1, 2, 3, and 4, but decreased in Group 5, and the flow duration curves showed characteristics of a head drop and tail lift. The flow regime alteration of the outlet section was more stable than before. This change had a negative impact on downstream fish reproduction and ecological protection. An attempt at ecological regulation was made to simulate the natural rising process of water.
Field-based estimation and modelling of distributed groundwater recharge in a Mediterranean karst catchment, Wadi Natuf, West Bank
Authors: Messerschmid Clemens , Sauter Martin , Lange Jens
Published: February 2020

Abstract. While groundwater recharge is one of the most prominently covered
subjects in hydrogeology, the spatial distribution of recharge has been
given relatively little attention, especially in semi-arid, karstic
aquifers. Under conditions of highly diverse geology, relief, vegetation and
land use, the complexity and variability of spatially distributed
hydrological processes remains a challenge in many regions around the world.
This is particularly true for hitherto ungauged basins, such as Wadi Natuf,
a 103 km2 large karstic Eastern Mediterranean watershed in the
Palestinian upstream mountain and recharge area of the Western Aquifer Basin
(WAB), which is shared with Israel in the coastal plain. In this first in a
series of two papers, distributed recharge is estimated and represented,
based on 7 years of extensive field observations and measurements and
based conceptually on observable physical landscape features such as
geology, land use and land cover (LU/LC) and especially soil conditions. For
the first time in the WAB, a forward calculated soil moisture and
percolation model (SMSP) was set up with parameters directly gained from
field observations. The model was parameterised in a strictly parsimonious
manner, as a one-dimensional model (a.k.a. “tank”, bucket or box model). This is
based on dominant hydrological processes, in particular saturation excess in
the soil column, and identifying patterns of linkage between different
landscape features. Average soil thickness was encountered at the range of
decimetres, rarely above one metre. Both soil thickness and LU/LC features,
such as terraced olive groves or forests as well as grassland or barren rock outcrops,
were found to be highly formation specific. This linkage allowed us to
further simplify the model and its requirements in a realistic manner for
eight soil moisture stations, chosen at six different geological formations
with typical soil and LU/LC representations. The main result of the model
was the determination of formation-specific recharge coefficients, spatially
ranging between 0 % and almost 60 % of annual rainfall or up to 300 mm a−1 in Wadi Natuf's climate. The karstified main aquifers showed recharge
coefficients (RC) above 40 % and even the less prominent slightly
aquitardal local aquifers reached RC values above 30 %. The model was
separately tested on two conceptual levels: on the level of basin form
(soil moisture) and basin response (signatures of peak recharge and local
spring discharge events) under well-controlled conditions in isolated
sub-catchments. In principle, our approach is applicable in many of the
scarcely gauged karstic groundwater basins around the world with a highly
diverse landscape and geology.
Impacts of Plant Growth-Promoting Rhizobacteria on Tropical Forage Grass in Brazil
Authors: Lopes Monyck Jeane dos Santos , Dias-Filho Moacyr Bernardino , Castro Thomaz Henrique dos Reis , Silva Edilson Ferreira da , Rêgo Marcela Cristiane Ferreira , Silva Gisele Barata da
Published: February 2020

The aim of this study was to evaluate the effects of plant growth-promoting rhizobacteria effects on anatomical characteristics and nutritional value of Brachiaria (Syn. Urochloa) brizantha cv. BRS Piatã. The experimental design applied was completely randomized design  with three treatments: (1) non-inoculated unfertilized-control plants (C-), (2) non-inoculated fertilized-control plants (C+) and (3) B. brizantha inoculated with Pseudomonas fluorescens (BRM-32111) and Burkholderia pyrrocinia (BRM-32113). The following parameters were evaluated at 35 days after seedling emergence: biomass production, plant height, net photosynthesis (A), water-use efficiency (WUE), chlorophyll (SPAD), anatomical and nutritional. The rhizobacteria modified the anatomy of the leaf, culm and roots of B. brizantha. They also increased the chlorophyll content, A, WUE, total soluble carbohydrates, starch and crude protein contents, N, P, Mg and Fe concentrations, plant height, root area and biomass production. Therefore, we conclude that co-inoculation with P. fluorescens (BRM-32111) and B. pyrrocinia (BRM-32113) modified the anatomy and biochemistry of B. brizantha, promoting growth and nutrient accumulation. Therefore, these findings set up the basis for additional exploratory studies, using these rhizobacteria as biotechnological innovation with potential of use as biofertilizer in B. brizantha, aiming higher productivity and nutritive value in a more eco-friendly and sustainable pasture production system.
Ransomware Evolution, Growth and Recommendation for Detection
Authors: Mohammad Adel Hamdan
Published: February 2020

Ransomware is a malicious program that can affect any person or organization. Ransomware is a complicated malicious attack that aims at lock or encrypt user files. Up to this date, there is no individual method, tool, which guarantee to protect against ransomware. Most tools available can detect some types of ransomware but it fails to detect other types of ransomware. In this research author talks about several methods, tools, procedures which can be taken to reduce the possibility of ransomware occurrences. Up to this moment, the main methods used by attacker to infect your machine are malicious emails and malicious links. After analyzing several reports written by some anti-viruses’ company such as Kaspersky ,McAfee, and several researches which talks about ransomware, author conclude two points: first point, educating users, following up a strict security policy, procedures and backup strategies are the best methods which can be taken to minimize the possibility of ransomware. second point, future methods to detect ransomware mainly will be based on artificial intelligence.
De procesinleiding
Authors: Reijntjes J.M.
Published: February 2020

De procesinleiding; het goede moment voor regie

De door de minister beoogde procesinleiding dreigt het aantal betekeningen sterk te verhogen. Verder blijven zijn voorstellen binnen de vertrouwde kaders; veel mogelijkheden van de moderne techniek worden onbenut gelaten.
Control of Milk Fermentation in Batch Bioreactor
Authors: Ritonja Jozef , Gorsek Andreja , Pecar Darja
Published: February 2020

In this paper, modelling and control of a batch bioreactor is studied. A main disadvantage of batch bioreactors compared to other types of bioreactors is their inability to introduce biological or/and chemical substances during operation. Therefore, possibility of bioreactor’s control by means of changing temperature was proposed, analyzed, and implemented. A new supplementary input/output dynamical mathematical model, which considers influence of heating and cooling on a bioprocess, was developed. On a basis of this model, a control system was designed and a method for tuning of the controller was suggested. Results show characteristics, applicability, and advantages of the presented approach.
A Survey of Physiciansâ€™ Viewpoints on Effective Factors in Internet of Things-Based Smart Hospitals Succes
Authors: Mahmoodi Soghra , Afshar Kazemi Mohammad Ali , Toloie Eshlaghy Abbas , Shadnoosh Nosratollah
Published: February 2020

Background: The Internet of Things (IOT) plays an important role in health care applications and is a system of interoperating computing devices, mechanical and digital machines. Methods: This descriptive study was carried out in 2017 using a pre-designed questionnaire, using Brender and Richards Heeks information system. It contains managerial, cultural, functional, technical, organizational, political and human factors relating to smart hospital based on internet of things. The questionnaire was completed by all 230 physicians working at university hospitals. Validity of the questionnaire was determined using content validity and its reliability was determined by test-retest method with 95% correlation coefficient. Data were analyzed by SPSS statistical software, using descriptive statistics as well as t-test and analysis of variance. Results: In this study, 149 (79.5%) males and 38 (20.5%) females participated. Based on the physicians’ viewpoints, percentage of agreement for managerial, cultural and organizational factors in creating a smart hospital was higher than other studied factors. Moreover, the viewpoint of male and female physicians on managerial, functional, organizational and human factors in implementing a smart hospital was significantly different. Conclusions: It seems that the management, organizational, and cultural factors are the most important factors in the implementation of smart hospital in Hormozgan University of Medical Sciences. It is necessary for planners and system owners to pay more attention to these factors.
HER2 Dual In Situ Hybridization: Correlations and Cautions
Authors: Troxell Megan , Sibley Richard K. , West Robert B. , Bean Gregory R. , Allison Kimberly H.
Published: February 2020

Context.—

Accurate HER2 testing in breast cancer is crucial for appropriate precision therapy. HER2 testing is most commonly accomplished by a combination of immunohistochemistry and in situ hybridization techniques, as gene amplification is closely tied to protein overexpression. During the last 5+ years, brightfield dual in situ hybridization (DISH) has replaced fluorescence methods (fluorescence in situ hybridization [FISH]) in some laboratories.

Objective.—

To analyze routine HER2 DISH performance in the field.

Design.—

We reviewed our experience with HER2 DISH performed at outside laboratories and referred for patient care.

Results.—

Of 273 identified retrospective DISH results, 55 had repeated FISH testing at our institution; 7 (13%) were discordant. Additional cases had technical flaws hampering appropriate scoring. In 23 cases (42%), HER2 DISH was performed without immunohistochemistry. Slide review of a prospective cohort of 42 consecutive DISH cases revealed 14 (33%) with technical or interpretative limitations potentially jeopardizing results. Commonly identified problems include lack of or weak signals in most tumor cells, and silver precipitate or red signals outside of nuclei, resulting in false-negative or false-positive interpretations, respectively. Further, 44% (24 of 55) of DISH reports lacked complete data, specifically average HER2 signals/cell.

Conclusions.—

While HER2 DISH can be an efficient and effective alternative to FISH, we illustrate pitfalls and reinforce that careful attention to slide quality and technical parameters are critically important. HER2 DISH cotesting with immunohistochemistry could help minimize false-negative or false-positive HER2 results.
Anticancer Activity of Silver Nanoparticle by Using Cassia auriculata Extract
Authors: Nawaz M. Prem , Banu A. Afroos , Mohamed S. Raja , Palanivelu M. , Ayeshamariam A.
Published: February 2020

In this study, green synthesis of silver nanoparticles (Ag NPs) has done using traditional herbal namely Cassia auriculata extract by the simple Green synthesis method. The synthesized Ag nanoparticles were studied by the characterization techniques includes X-ray diffraction (XRD) crystallography for nature of crystalline with relevant parameters, Transmission electron microscopy (TEM) for particle size as well as the SAED patterns for amorphous, crystalline or polynanocrystalline and Photoluminescence analysis were carried out for the prepared NPs. Ag NPs were fabricated utilizing Phyto-aquatic extract of Cassia auriculata which act as a reducing agent, and it was converted into a precursor solution to coat on cotton fabrics for antibacterial applications. To further, its performance on anticancer application was studied for Michigan Cancer Foundation-7 (MCF-7) line breast cancer.
The Prevalence of Salmonellosis in Patients with Malaria Attending an Urban Hospital in Douala, Littoral Region, Cameroon
Authors: Njolle Alice Belle , Tientche Bonaventure , Asaah Smith , Forfuet David Foncha , Kamga Henri Lucien Fouamno
Published: February 2020

Aims: This study was carried out to determine the rate of co-infection of Malaria/typhoid fever among patients attending the hospital.

Study Design: The study was a hospital based cross-sectional.

Place and Duration of Study: The study was carried out at the Centre Medical Camrail, de Bassa (CMCD), Douala, Littoral Region, Cameroon, from April to May 2015.

Methods: One hundred and sixty (160) blood and stool Samples were collected. Blood samples were subjected to microscopic examination used for the malaria parasite. Widal agglutination slide and tube test were performed for the identification of antibodies to Salmonella typhi and stool culture used for isolation of Salmonella species.

Results: Overall malaria prevalence was 19.4% (31/160) with a geometric mean parasite density (GMPD) of 788.62±1945.763 parasites/µL of blood. The overall prevalence of typhoid fever by stool culture was 32.5% (52/160) while malaria/typhoid fever and malaria/non-typhoidal salmonella co-infection rates were 29% (9) and 7% (3) respectively. Of the positive malaria samples, 03 (4%) were identified as Salmonella typhi, 4 (5.3%) as S. typhimirium, 02 (2.6%) as S. paratyphi A and 03 (4%) as S. paratyphi B. They were no significant relationship between malaria and typhoid fever (χ2=.609; p= .738). Typhoid fever was grossly under diagnosed by Widal test 1.25% (2/160) compared to stool culture 34.4% (55/160).

Conclusion: The study showed the rate of co-infections of malaria and typhoid fever is relatively high. Malaria was the most prevalent disease among febrile patients in the study area. There was a substantial result discrepancy between Widal test and stool culture for the diagnosis of typhoid fever.
Does community violence exposure moderate the associations between maternal spanking and early child behavior problems?
Authors: Ma Julie , Grogan‐Kaylor Andrew , Lee Shawna J.
Published: February 2020

A robust research literature links parental spanking with negative behavioral outcomes for children, however, it remains unclear whether conditions in the community may moderate the associations between spanking and behavior problems in early childhood. In the current study, we examined whether community violence exposure moderated the associations of maternal spanking with externalizing and internalizing behavior problems of young children. The sample used in this study was urban families and their children ages 3–5 (n = 2,472). We used fixed effects regression models, which yield stronger statistical control for baseline behavior problems, selection bias, and omitted variables bias. Mother's spanking was associated with elevated levels of both externalizing (β = .037, p < .001) and internalizing (β = .016, p < .001) behavior problems. Community violence exposure also predicted higher levels of externalizing (β = .071, p < .01) and internalizing (β = .043, p < .05) behavior problems. Community violence exposure did not moderate the associations between maternal spanking and behavior problems. Professionals working with families should promote the use of nonphysical disciplinary practices, regardless of the level of violence and crime in the community in which the family resides.
The Phenotype of Axial Spondyloarthritis: Is It Dependent on HLA–B27 Status?
Authors: Coates Laura C. , Baraliakos Xenofon , Blanco Francisco J. , Blanco‐Morales Elena Alonso , Braun Jurgen , Chandran Vinod , Fernandez‐Sueiro Jose Luis , FitzGerald Oliver , Gallagher Phil , Gladman Dafna D. , Gubar Elena , Korotaeva Tatiana , Loginova Elena , Lubrano Ennio , Mulero Juan , Pinto‐Tasende Jose , Queiro Ruben , Sanz Sanz Jesús , Szentpetery Agnes , Helliwell Philip S.
Published: February 2020

Objective

To describe the radiographic phenotype of axial spondyloarthritis (SpA) according to the presence of HLA–B27.

Methods

An international collaboration compared the radiographic phenotype of axial SpA according to HLA–B27 status. Patients with ankylosing spondylitis (AS) and axial psoriatic arthritis (PsA) were collected. Radiographs were read centrally, blinded to clinical details. The symmetry of the sacroiliac joints and lumbar syndesmophytes and the morphology of syndesmophytes (typical marginal versus atypical chunky), together with the modified Stoke Ankylosing Spondylitis Spine Score and the Psoriatic Arthritis Spondylitis Radiographic Index, were recorded.

Results

A total of 244 patients with PsA and 198 patients with AS were included. In PsA, 60 patients (25%) were HLA–B27 positive while in AS, 148 patients (75%) were HLA–B27 positive. Patients with HLA–B27 were younger and more often male and had a longer duration of disease. In multivariable logistic regression, HLA–B27 was significantly associated with syndesmophyte symmetry (odds ratio [OR] 3.02 [95% confidence interval (95% CI) 1.38, 6.61]) and marginal syndesmophytes (OR 1.97 [95% CI 1.16, 3.36]) but not with sacroiliac symmetry. Mean radiographic scores were higher for patients with HLA–B27.

Conclusion

Patients with axial SpA who are positive for HLA–B27 have more severe radiographic damage, more marginal syndesmophytes, and more frequent syndesmophyte symmetry compared to patients who are negative for HLA–B27.
Contact Engineering of Layered MoS2 via Chemically Dipping Treatments
Authors: Bang Seungho , Lee Sangyeob , Rai Amritesh , Duong Ngoc Thanh , Kawk Iljo , Wolf Steven , Chung Choong‐Heui , Banerjee Sanjay K. , Kummel Andrew C. , Jeong Mun Seok , Park Jun Hong
Published: February 2020

The performance of electronic/optoelectronic devices is governed by carrier injection through metal–semiconductor contact; therefore, it is crucial to employ low‐resistance source/drain contacts. However, unintentional introduction of extrinsic defects, such as substoichiometric oxidation states at the metal–semiconductor interface, can degrade carrier injection. In this report, controlling the unintentional extrinsic defect states in layered MoS2 is demonstrated using a two‐step chemical treatment, (NH4)2S(aq) treatment and vacuum annealing, to enhance the contact behavior of metal/MoS2 interfaces. The two‐step treatment induces changes in the contact of single layer MoS2 field effect transistors from nonlinear Schottky to Ohmic behavior, along with a reduction of contact resistance from 35.2 to 5.2 kΩ. Moreover, the enhancement of ION and electron field effect mobility of single layer MoS2 field effect transistors is nearly double for n‐branch operation. This enhanced contact behavior resulting from the two‐step treatment is likely due to the removal of oxidation defects, which can be unintentionally introduced during synthesis or fabrication processes. The removal of oxygen defects is confirmed by scanning tunneling microscopy and X‐ray photoelectron spectroscopy. This two‐step (NH4)2S(aq) chemical functionalization process provides a facile pathway to controlling the defect states in transition metal dichalcogenides (TMDs), to enhance the metal‐contact behavior of TMDs.
Core Fluorination Enhances Solubility and Ambient Stability of an IDT‐Based n‐Type Semiconductor in Transistor Devices
Authors: Hodsden Thomas , Thorley Karl J. , Panidi Julianna , Basu Aniruddha , Marsh Adam V. , Dai Haojie , White Andrew J. P. , Wang Changsheng , Mitchell William , Glöcklhofer Florian , Anthopoulos Thomas D. , Heeney Martin
Published: February 2020

The synthesis of a novel fluorinated n‐type small molecule based on an indacenodithiophene core is reported. Fluorination is found to have a significant impact on the physical properties, including a surprisingly dramatic improvement in solubility, in addition to effectively stabilizing the lowest‐unoccupied molecular orbital energy (−4.24 eV). Single‐crystal analysis and density functional theory calculations indicate the improved solubility can be attributed to backbone torsion resulting from the positioning of the fluorine group in close proximity to the strongly electron‐withdrawing dicyanomethylene group. Organic thin‐film transistors made via blade coating display high electron mobility (up to 0.49 cm2 V−1 s−1) along with good retention of performance in ambient conditions.
Phase Engineering of High‐Entropy Alloys
Authors: Chang Xuejiao , Zeng Mengqi , Liu Keli , Fu Lei
Published: February 2020

High‐entropy alloys (HEAs) are based on five or more principal elements with equal or nearly equal molar fractions and possess many significant advantages over traditional alloys, including high strength and hardness, excellent corrosion resistance, outstanding thermal stability, and irradiation resistance. Phase structure plays a vital role in determining the property of HEAs. For further enhancing the performance of HEAs in various application fields, a controllable synthesis with desired phases is required. In this review, the diverse phase structures of HEAs and the related properties are first introduced. Then, alternative tuning strategies to promote the desired phase structure of HEAs are focused upon. Property adjusting of phase‐engineered HEAs is also discussed in depth. Lastly, some insights into the challenges and future prospects in this rapidly emerging research field are provided.
Inverse Design Strategies for 3D Surfaces Formed by Mechanically Guided Assembly
Authors: Fan Zhichao , Yang Yiyuan , Zhang Fan , Xu Zheng , Zhao Hangbo , Wang Taoyi , Song Honglie , Huang Yonggang , Rogers John A. , Zhang Yihui
Published: February 2020

Deterministic transformations of 2D patterns of materials into well‐controlled 3D mesostructures serve as the basis for manufacturing methods that can bypass limitations of conventional 3D micro/nanofabrication. Here, guided mechanical buckling processes provide access to a rich range of complex 3D mesostructures in high‐performance materials, from inorganic and organic semiconductors, metals and dielectrics, to ceramics and even 2D materials (e.g., graphene, MoS2). Previous studies demonstrate that iterative computational procedures can define design parameters for certain targeted 3D configurations, but without the ability to address complex shapes. A technical need is in efficient, generalized inverse design algorithms that directly yield sets of optimized parameters. Here, such schemes are introduced, where the distributions of thicknesses across arrays of separated or interconnected ribbons provide scalable routes to 3D surfaces with a broad range of targeted shapes. Specifically, discretizing desired shapes into 2D ribbon components allows for analytic solutions to the inverse design of centrally symmetric and even general surfaces, in an approximate manner. Combined theoretical, numerical, and experimental studies of ≈20 different 3D structures with characteristic sizes (e.g., ribbon width) ranging from ≈200 µm to ≈2 cm and with geometries that resemble hemispheres, fire balloons, flowers, concave lenses, saddle surfaces, waterdrops, and rodents, illustrate the essential ideas.
Chlorosome‐Like Molecular Aggregation of Chlorophyll Derivative on Ti3C2Tx MXene Nanosheets for Efficient Noble Metal‐Free Photocatalytic Hydrogen Evolution
Authors: Li Yuanlin , Chen Xin , Sun Yuliang , Meng Xing , Dall'Agnese Yohan , Chen Gang , Dall'Agnese Chunxiang , Ren Hangchen , Sasaki Shin‐ichi , Tamiaki Hitoshi , Wang Xiao‐Feng
Published: February 2020

Efficient photocatalytic hydrogen evolution reaction (HER) in the visible‐to‐near infrared region at a low cost remains a challenging issue. This work demonstrates the fabrication of organic‐inorganic composites by deposition of supramolecular aggregates of a chlorophyll derivative, namely, zinc methyl 3‐devinyl‐3‐hydroxymethyl‐pyropheophorbide a (Chl) on the surface of Ti3C2Tx MXene with 2D accordion‐like morphology. This composite material is employed as noble metal‐free catalyst in photocatalytic HER under the white light illumination, where Chl serves as a small molecule organic semiconductor component instead of ordinary inorganic and polymer organic semiconductors such as TiO2 and g‐C3N4, and Ti3C2Tx serves as a co‐catalyst. Different composition ratios of Chl/Ti3C2Tx are compared for their light‐harvesting ability, morphology, charge transfer efficiency, and photocatalytic performance. The best HER performance is found to be as high as 52 ± 5 µmol h−1 gcat−1 after optimization. Such a large HER activity is attributed to the efficient light harvesting followed by exciton transfer in Chl aggregates and the resultant charge separation at the interface of Chl/Ti3C2Tx.
Liquid‐Exfoliated Few‐Layer InSe Nanosheets for Broadband Nonlinear All‐Optical Applications
Authors: Liao Yunlong , Shan Youxian , Wu Leiming , Xiang Yuanjiang , Dai Xiaoyu
Published: February 2020

The nonlinear optical response of 2D materials has attracted wide attention in the recent year due to their strong nonlinearity and broadband characteristics. A new optical scheme is presented enabling the implementation of the broadband nonlinear optical response and their all‐optical applications of few‐layered InSe nanosheets. First, few‐layer InSe nanosheets are synthesized by using the liquid‐phase exfoliated method; then the third‐order nonlinear susceptibility is measured with the spatial self‐phase modulation. Based on the obtained nonlinear optical response, a method is proposed for forming a nonreciprocal propagation photonic diode based on a mixed structure of InSe/C3N4. In addition, through the cross‐phase modulation of the two beams, the all‐optical switches and all‐optical information conversion have also been discussed. The implementations of these few‐layered InSe‐based all‐optical devices show that the layered InSe is indeed an excellent candidate for use in future all‐optical photonic circuits as an optical diode and optical switching.
Low‐Cost, Scalable, and Reusable Photothermal Layers for Highly Efficient Solar Steam Generation and Versatile Energy Conversion
Authors: Shan Xiaoli , Zhao Aiqing , Lin Yawen , Hu Yujing , Di Yunsong , Liu Cihui , Gan Zhixing
Published: February 2020

Solar steam generation (SSG) based on the photothermal effect has been considered to be a promising avenue for freshwater production. However, the fabrication of highly‐efficient photothermal layers, at large‐scale and low‐cost is still a challenge, hindering practical applications. Herein, it is demonstrated that carbonized towel‐gourd sponges (CTGS) are excellent photothermal materials. And a capillarity‐driven interfacial self‐coating method is developed to prepare the super‐hydrophilic CTGS/paper photothermal layer. The SSG device based on the CTGS/paper exhibits a high evaporation rate of 1.53 kg m−2 h−1 with an efficiency of 95.9% under 1 sun irradiation. The high evaporation rate only slightly reduces when confronting the diverse and complex practical SSG conditions, such as seawater and waste water. Moreover, CTGS/paper has the advantages of simple preparation, recyclablability, low‐cost (≈4 $ per m2), high‐efficiency, flexibility, and scalability, which are the important prerequisites for promoting SSG techniques for industrialization and practical applications. In addition, the versatile energy conversion ability of the CTGS/paper is also demonstrated. Assisted by the photothermal effect of CTGS/paper, solar energy is converted to mechanical energy and electricity.
The Case for a Lemon Bioeconomy
Authors: Ciriminna Rosaria , Fidalgo Alexandra , Scurria Antonino , Sciortino Marzia , Lino Claudia , Meneguzzo Francesco , Ilharco Laura M. , Pagliaro Mario
Published: February 2020

Today's green chemistry technologies open the route to a broader and richer economy for lemons, well beyond the fresh fruit and fruit juice markets. This has important social, environmental, and economic consequences for all lemon‐growing countries and for many industries. Which are the new bioproducts obtainable from lemon and its by‐products? And what are the unforeseen new applications of old bioproducts such as pectin? Following an updated outlook on the global lemon economy, it is shown through selected examples how the lemon bioeconomy might unfold in the course of the next few years (2021–2025).
A New Route for Dioxygen Activation Uncovered from Quantum Mechanics Investigations of X‐Ray‐Diffraction‐Captured Intermediates of the Ferroxidase Reaction of Ferritins from Gram‐Negative Bacteria
Authors: Pietra Francesco
Published: February 2020

Following the recent reassessment from X‐ray‐diffraction‐caught short‐path uptake to wide permeation of the S20A mutant Escherichia coli ferritin by ferrous ions, what happens when dioxygen gets to the diiron system is investigated. It is shown that the previously X‐ray‐caught situation of an unbound‐dioxygen diferrous state actually is an ephemeral state that changes into a P‐type peroxodiferric state, while a water molecule moves to bridge the two ferric ions, in what appears to be a remarkable redox process. All this stems from density functional theory (DFT)‐based quantum mechanics‐molecular mechanics and broken symmetry (BS) calculations that are extended to X‐ray‐diffraction‐caught oxodiferric and I‐type peroxodiferric systems from other subunits of the same crystal structure, validating them while determining antiferromagnetic coupling with all such diiron systems except the oxodiferric one. The latter converged, on BS, to ferromagnetic coupling under a wide variety of hybrid DFT functionals and basis sets. The trend of the Heisenberg J coupling reflects and substantiates the structures of the diiron core.
A Metal–Organic Framework Nanosheet‐Assembled Frame Film with High Permeability and Stability
Authors: Huang Chuanhui , Liu Cong , Chen Xiangyu , Xue Zhenjie , Liu Keyan , Qiao Xuezhi , Li Xiao , Lu Zhili , Zhang Lan , Lin Zhenyu , Wang Tie
Published: February 2020

The engineering of metal–organic frameworks (MOFs) into membranes and films is being investigated, to transform laboratory‐synthesized MOFs into industrially viable products for a range of attractive applications. However, rational design and construction of highly permeable MOF thin films, without trade‐offs in terms of structural mechanical stability, remains a significant challenge. Herein, a simple, general strategy is reported to prepare thin MOF nanosheet (NS)‐assembled frame film via heteroepitaxial growth from metal hydroxide film. As the thin MOF NS‐assembled film significantly enhances the permeability of mass though the film, the resultant gold nanoparticle (Au NP)@MOF film exhibits much higher catalytic efficiency than the Au NP@MOF bulk film. Meanwhile, the unique framework of the MOF NS‐assembled film resists torsion and collapse, so the composite catalyst exhibits long‐term stability.
Net return and risk analysis of winter cover crops in dryland cotton systems
Authors: Fan Yubing , Liu Yangxuan , DeLaune Paul B. , Mubvumba Partson , Park Seong C. , Bevers Stanley J.
Published: February 2020

Winter cover crop and no‐till are two promising conservation practices to reduce soil erosion and promote long‐term sustainability. This research evaluates the net returns of two different tillage methods and five cover crop treatments in dryland cotton (Gossypium hirsutum L.) production and identifies risk‐efficient tillage and cover crop management practices. Four‐year field experiments (2013−2016) were conducted for a continuous cotton production system under conventional tillage and no‐till without a cover crop, as well as no‐till with cover crops including winter wheat (Triticum aestivum L.), crimson clover (Trifolium incarnatum L.), Austrian winter field pea (Pisum sativum L.), hairy vetch (Vicia villosa Roth), and mixed cover crops. Results showed no statistical differences in lint yields (P = .98) or net returns (P = .82). No‐till with crimson clover decreased yield variation compared to conventional tillage, while hairy vetch and mixed cover crops increased yield variation. The average net returns were US$454 and $461 ha−1 for conventional tillage and no‐till without a cover crop, respectively. The average net returns ranged from $346 to $389 ha−1 for the cover crop treatments. Producers have a higher probability of getting a higher net return if switching from conventional tillage to no‐till. The risk analysis results showed that no‐till without a cover crop was the most preferred practice by risk‐neutral, somewhat and rather risk‐averse producers. For very and extremely risk‐averse producers, no‐till with crimson clover was the most preferred management practice.
Cutaneous findings of familial cerebral cavernous malformation syndrome due to the common Hispanic mutation
Authors: Manole Athanasios K. , Forrester Vernon J. , Zlotoff Barrett J. , Hart Blaine L. , Morrison Leslie A.
Published: February 2020

Familial cerebral cavernous malformations due to the common Hispanic mutation (FCCM1‐CHM) is an endemic condition among the Hispanic population of the Southwestern United States associated with significant morbidity and mortality. Cutaneous vascular malformations (CVMs) can be found in individuals with FCCM1‐CHM, but their morphology, prevalence, and association with cerebral cavernous malformations (CCMs) has not been well characterized. A cross‐sectional study of 140 individuals with confirmed FCCM1‐CHM was performed with statistical analyses of CVM, CCM, and patient characteristics. We then compared these findings to other cohorts with Familial cerebral cavernous malformations (FCCM) due to other mutations. We observed a higher overall prevalence and a different predominant morphological subtype of CVM compared to previous FCCM cohorts. While the number of CVMs was not a reliable indicator of the number of CCMs present, each person with one or more CVMs had evidence of central nervous system (CNS) disease. Awareness of the morphology of these cutaneous lesions can aid in the diagnosis of individuals with FCCM‐CHM in Hispanic patients or those with family history of CCM.
Carbon Dioxide Activation at Metal Centers: Evolution of Charge Transfer from Mg .+ to CO2 in [MgCO2(H2O)n].+, n=0–8
Authors: Barwa Erik , Pascher Tobias F. , Ončák Milan , van der Linde Christian , Beyer Martin K.
Published: February 2020

We investigate activation of carbon dioxide by singly charged hydrated magnesium cations Mg .+(H2O)n, through infrared multiple photon dissociation (IRMPD) spectroscopy combined with quantum chemical calculations. The spectra of [MgCO2(H2O)n].+ in the 1250–4000 cm−1 region show a sharp transition from n=2 to n=3 for the position of the CO2 antisymmetric stretching mode. This is evidence for the activation of CO2 via charge transfer from Mg .+ to CO2 for n≥3, while smaller clusters feature linear CO2 coordinated end‐on to the metal center. Starting with n=5, we see a further conformational change, with CO2.− coordination to Mg2+ gradually shifting from bidentate to monodentate, consistent with preferential hexa‐coordination of Mg2+. Our results reveal in detail how hydration promotes CO2 activation by charge transfer at metal centers.
Output optimization of scalar and 2‐dimension time‐varying nonlinear systems using zeroing dynamics
Authors: Zhang Yunong , Shi Nini , Yang Min , Guo Jinjin , Chen Jianrong
Published: February 2020

The optimal control of time‐varying nonlinear systems is an important research topic and faces many difficulties and challenges, but also has substantial benefits. In this paper, the output optimization of scalar time‐varying nonlinear (STVN) system and 2‐dimension time‐varying nonlinear (2DTVN) system is considered. The zeroing dynamics (ZD) method, which can solve the time‐varying problems flexibly and effectively, has been extensively used in recent years. By introducing the ZD method, the time‐varying optimal system state is attained, and the controller with the optimal output is designed. Meanwhile, the direct dynamics (DD) method is presented to further illustrate the superiority of the ZD method. Theoretical analyses prove that the ZD method has a faster convergence rate (that is, exponential convergence). In addition, the effectiveness and feasibility of the ZD method for solving the output optimization of STVN and 2DTVN systems are verified by numerical experiments, and further substantiated via output optimization of a two‐wheeled mobile robot.
Inconsistencies in repeated refugee status decisions
Authors: Pärnamets Philip , Tagesson Alexander , Wallin Annika
Published: February 2020

Consistency in civil servant decisions is paramount to upholding judicial equality for citizens and individuals seeking safety through governmental intervention. We investigated refugee status decisions made by a sample of civil servants at the Swedish Migration Agency. We hypothesized, based on the emotional demands such decisions bring with them, that participants would exhibit a compassion fade effect such that refugee status was less likely to be granted over time. To test this, we administered a questionnaire containing brief presentations of asylum seekers and asked participants to judge how likely they would be to give refugee status to the person. Crucially the first, middle, and final case presented were matched on decision relevant characteristics. Consistent with our hypothesis, we saw a significant decline in ratings. These effects were accentuated by the amount of time a participant had worked at the agency, consistent with depletion of affective resources, and attenuated in workers with greater responsibility and additional training. We conclude that active regulation of empathic and affective responses to asylum seekers may play a role in determining the outcome in refugee status decisions.
The link between student‐perceived teacher talk and student enjoyment, anxiety and discursive engagement in the classroom
Authors: Chen Gaowei , Zhang Jiahong , Chan Carol K. K. , Michaels Sarah , Resnick Lauren B. , Huang Xiaorui
Published: February 2020

This study seeks to understand the emotional connection of teachers' academically productive talk (APT) with student learning from the students' perspective. Using a sample of 2,225 students (N7th grade = 1,146 and N8th grade = 1,079) from 16 middle schools in a city of China, we investigate the relationship between students' perceptions of their teachers’ APT, student emotions (enjoyment and anxiety) and their discursive engagement with others in the mathematics classroom. Results from structural equation modelling and mediation analysis show that after controlling for gender, family resources and mathematics achievement, student‐perceived teacher APT was positively associated with their discursive engagement with classmates. Furthermore, student enjoyment and anxiety in class mediated the relationship between student‐perceived teacher APT and student discursive engagement with classmates. Multi‐group analysis revealed that the model was invariant across genders and grades, indicating that the associations were applicable to male and female students as well as to seventh and eighth graders. These findings shed light on the emotional relationship of teacher APT with the discursive engagement of their students. Although prior research observes a positive relationship between teacher productive classroom talk and student discursive engagement primarily through classroom observations and teacher reflections, this study provides evidence from the students’ perspective and highlights the mediating role of student emotions in the relationship.