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The Open Quantum Materials Database (OQMD): assessing the accuracy of DFT formation energies

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npj Computational Materials 2015年第1期1卷 15-29页

作者： scott Kirklin James e Saal Bryce Meredig Alex Thompson Jeff W Doak Muratahan Aykol Stephan rühl Chris Wolverton Department of Materials Science and engineering Northwestern UniversityEvanstonILUSA FIZ Karlsruhe—Leibniz Institute for Information Infrastructure Eggenstein-LeopoldshafenGermany

The Open Quantum Materials Database(OQMD)is a high-throughput database currently consisting of nearly 300,000 density functional theory(DFT)total energy calculations of compounds from the Inorganic Crystal Structure Database(ICSD)and decorations of commonly occurring crystal *** maximise the impact of these data,the entire database is being made available,without restrictions,at ***/*** this paper,we outline the structure and contents of the database,and then use it to evaluate the accuracy of the calculations therein by comparing DFT predictions with experimental measurements for the stability of all elemental ground-state structures and 1,670 experimental formation energies of *** represents the largest comparison between DFT and experimental formation energies to *** apparent mean absolute error between experimental measurements and our calculations is 0.096 eV/*** order to estimate how much error to attribute to the DFT calculations,we also examine deviation between different experimental measurements themselves where multiple sources are available,and find a surprisingly large mean absolute error of 0.082 eV/***,we suggest that a significant fraction of the error between DFT and experimental formation energies may be attributed to experimental ***,we evaluate the stability of compounds in the OQMD(including compounds obtained from the ICSD as well as hypothetical structures),which allows us to predict the existence of~3,200 new compounds that have not been experimentally characterised and uncover trends in material discovery,based on historical data available within the ICSD.

关键词： Quantum DFT Open

Numerical modeling of the effects of roughness on flow and eddy formation in fractures

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Journal of rock Mechanics and Geotechnical engineering 2017年第1期9卷 105-115页

作者： scott Briggs Bryan W. Karney Brent e. Sleep University of Toronto Toronto M5S 1A4 Canada

The effect of roughness on flow in fractures was investigated using lattice Boltzmann method(LBM).Simulations were conducted for both statistically generated hypothetical fractures and a natural dolomite fracture. The effect of increasing roughness on effective hydraulic aperture, Izbash and Forchheimer parameters with increasing reynolds number(re) ranging from 0.01 to 500 was examined. The growth of complex flow features, such as eddies arising near the fracture surface, was directly associated with changes in surface roughness. rapid eddy growth above re values of 1, followed by less rapid growth at higher re values, suggested a three-zone nonlinear model for flow in rough fractures. This three-zone model, relating effective hydraulic conductivity to re, was also found to be appropriate for the simulation of water flow in the natural dolomite fracture. Increasing fracture roughness led to greater eddy volumes and lower effective hydraulic conductivities for the same re values.

关键词： Hydrogeology Fracture flow Fracture roughness Computational fluid dynamics Lattice Boltzmann method(LBM)

effects of N on Plant response to Heat-wave:A Field Study with Prairie Vegetation

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Journal of Integrative Plant Biology 2008年第11期50卷 1416-1425页

作者： Dan Wang scott A. Heckathorn Kumar Mainali e. William Hamilton Department of environmental Sciences University of Toledo Toledo Ohio 43606 USA Department of Biology Washington and Lee University Lexington Virginia 24450 USA

More intense, more frequent, and longer heat-waves are expected in the future due to global warming, which could have dramatic ecological impacts. Increasing nitrogen （N） availability and its dynamics will likely impact plant responses to heat stress and carbon （C） sequestration in terrestrial ecosystems. This field study examined the effects of N availability on plant response to heat-stress （HS） treatment in naturally-occurring vegetation. HS （5 d at ambient or 40.5 ℃） and N treatments （±N） were applied to 16 1 m^2 plots in restored prairie vegetation dominated by Andropogon gerardii （warm-season C4 grass） and Solidago canadensis （warm-season C3 forb）. Before, during, and after HS, air, canopy, and soil temperature were monitored; net CO2 assimilation （Pn）, quantum yield of photosystem Ⅱ （ФpsⅡ）, stomatal conductance （gs）, and leaf water potential （ψw） of the dominant species and soil respiration （rsoll） of each plot were measured daily during HS. One week after HS, plots were harvested, and C% and N% were determined for rhizosphere and bulk soil, and above-ground tissue （green/senescent leaf, stem, and flower）. Photosynthetic N-use efficiency （PNUe） and N resorption rate （Nrr） were calculated. HS decreased Pn, gs, ψw, and PNUe for both species, and ＋N treatment generally increased these variables （±HS）, but often slowed their post-HS recovery. Aboveground biomass tended to decrease with HS in both species （and for green leaf mass in S. canadensis）, but decrease with ＋N for A. gerardii and increase with ＋N for S. canadensis. For A. gerardii, HS tended to decrease N% in green tissues with ＋N, whereas in S. canadensis, HS increased N% in green leaves. Added N decreased Nrr for A. gerardii and HS increased Nrr for S. canadensis. These results suggest that heat waves, though transient, could have significant effects on plants, communities, and ecosystem N cycling, and N can influence the effect of heat waves.

关键词： global climate change heat stress N resorption rate photosynthesis photosynthetic N-use efficiency.

How Specific is Non-Hypersensitive Host and Nonhost resistance of Barley to rust and Mildew Fungi?

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Journal of Integrative Agriculture 2014年第2期13卷 244-254页

作者： Niks r e Laboratory of Plant Breeding Wageningen UniversityP.O.Box 3866700 AJ WageningenThe Netherlands

Full nonhost resistance can be defined as immunity, displayed by an entire plant species against all genotypes of a plant pathogen. Interesting biological questions are, whether the genes responsible for the nonhost status of a plant species have a general or a specific effectiveness to heterologous （＂nonhost＂） pathogens？ Is the nonhost resistance to pathogens of plant species that are related to the nonhost based on r-genes or on other types of genes？ We study this question in barley （Hordeum vulgare L.）, which is a near-nonhost to several rusts （Puccinia） of cereals and grasses. By crosses and selection we accumulated susceptibility and developed an experimental line, SusPtrit, with high susceptibility to at least nine different heterologous rust taxa such as the wheat and Agropyron leaf rusts （P. triticina and P. persistens, respectively）. At the microscopic level there is also some variation among barley accessions in the degree that the heterologous wheat powdery mildew （Blumeria graminis ***. tritici） is able to form haustoria in epidermal cells. So, also the genetics of the variation in level of nonhost resistance to heterologous mildew fungi can be studied in barley. Our data obtained on mapping populations involving three regular nonhost-immune accessions （Vada, Cebada Capa and Golden Promise） suggest that nonhost resistance is the joined effect of multiple, quantitative genes （QTLs） and very occasionally a major gene （r-gene？） is involved. Most QTLs have effect to only one or two heterologous rusts, but some have a wider spectrum. This was confirmed in a set of QTL-NILs. Those QTL-NILs are used to fine-map the effective genes. In some cases, a QTL region with effectiveness to several heterologous rusts might be a cluster of genes with a more narrow spectrum of effectiveness. Our evidence suggests that nonhost resistance in barley to rust and powdery mildew fungi of related Gramineae is not due to r-genes, but to pathogen species-specific quantitative resi

关键词： genetics specificity basal resistance

Investigating the impact of the universal function of the nuclear proximity potential in heavy-ion fusion cross sections

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Communications in Theoretical Physics 2024年第5期76卷 86-93页

作者： r Gharaei e Sarvari Department of Physics Sciences FacultyHakim Sabzevari UniversityPO Box 397SabzevarIran Department of Physics Faculty of ScienceFerdowsi University of MashhadPO Box 91775-1436MashhadIran Science Faculty Department of PhysicsTarbiat Modares UniversityTehranIran

The fusion barriers and cross sections of 15 colliding systems with 320≤Z_(1)Z_(2)≤1512 are investigated in detail to understand the influence of the universal function of proximity potential formalism in the heavy-ion fusion *** realize this goal,we select three versions of the phenomenological proximity potentials,including Prox.77,Zhang 2013,and Guo 2013,to calculate the nucleus-nucleus *** experimental fusion cross sections for the selected reactions are analyzed using the standard coupled-channel calculations,including couplings to the low-lying 2^(+)and 3^(-)states in the target and *** calculated results show that the universal functions of the Guo 2013 and Prox.77 models provide the lowest and highest fusion barriers,*** addition,it is found that the height of the fusion barriers is enhanced by increasing the mass number of the projectile from light to heavy *** highest sensitivity to the mass number of the projectile belongs to the results of Prox.77.A discussion is also presented on the influence of the universal function on the radial behavior of the interaction potential in the allowed region for overlapping *** results reveal that the best fit to the experimental data of the fusion cross sections for the reactions involving light and medium nuclei is obtained using the universal function of the Zhang 2013 *** the heavier systems,the results of the Guo 2013 model at sub-barrier energies provide a good description of the available data.

关键词： fusion reactions proximity-type potentials universal function coupled-channel calculations

Scoping out the future:The application of artificial intelligence to gastrointestinal endoscopy

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World Journal of Gastrointestinal Oncology 2022年第5期14卷 989-1001页

作者： scott B Minchenberg Trent Walradt Jeremy r Glissen Brown Department of Internal Medicine Beth Israel Deaconess Medical CenterBostonMA 02130United States Division of Gastroenterology Beth Israel Deaconess Medical CenterBostonMA 02130United States

Artificial intelligence(AI)is a quickly expanding field in gastrointestinal *** there are a myriad of applications of AI ranging from identification of bleeding to predicting outcomes in patients with inflammatory bowel disease,a great deal of research has focused on the identification and classification of gastrointestinal *** of the initial randomized,prospective trials utilizing AI in clinical medicine have centered on polyp detection during screening *** addition to work focused on colorectal cancer,AI systems have also been applied to gastric,esophageal,pancreatic,and liver *** promising results in initial studies,the generalizability of most of these AI systems have not yet been *** this article we review recent developments in the field of AI applied to gastrointestinal oncology.

关键词： Artificial intelligence Oncology Gastroenterology endoscopy Machine learning Computer-assisted decision making Computer-aided detection Computer-aided diagnosis

electronic,optical,and mechanical properties of BN,AlN,and InN with zinc-blende structure under pressure

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Chinese Physics B 2017年第8期26卷 320-327页

作者： A r Degheidy e B elkenany Department of Physics Faculty of ScienceMansoura UniversityP.O.Box 35516MansouraEgypt

In this work, the electronic, optical, and mechanical properties of BN, AlN, and InN under the action of pressure are calculated. For each of these compounds, the energy band structure, band gaps（e^L_g, e~Γ_g, e^X_g）, refractive index（n）,dielectric constants（ε_∞, ε_0）, elastic constants（C_11, C_12, C_44）, and relevant parameters such as bulk（B_u）, shear（S_h）, and Young＇s（Y_0） moduli are studied, and other important parameters such as bond-stretching（α）, bond-bending（β） force constant, internal-strain parameter（ζ）, effective charges（e~＊_T, Z~＊）, anisotropy factor（I_s）, Poisson＇s ratio（P_o）, Cauchy ratio（C_a）, the ductility index（μ_D）, and linear compressibility（C0_） are also calculated. The effects of pressure on all studied properties are investigated. Our results are in good agreement with the available experimental and theoretical data for BN,AlN, and InN.

关键词： electronic properties optical properties mechanical properties BN A1N InN

Variable retention in Tasmania, Australia: trends over 16 years of monitoring and adaptive management

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ecological Processes 2019年第1期8卷 305-317页

作者： robyn e.scott Mark G.Neyland Susan C.Baker Sustainable Timber Tasmania 99 Bathurst StHobartTasmania 7001Australia School of Natural Sciences and ArC Centre for Forest Value University of TasmaniaPrivate Bag 55HobartTasmania 7001Australia

Background:Variable retention harvesting using aggregated retention(ArN)has been applied in some Tasmanian wet eucalypt forests for>15 *** of ArN in Tasmania differs from most other regions,as forest influence(or the proximity of harvested areas to long-term retention)is primarily used to distinguish ArN from clearfelling rather than retention level,and broadcast burning is used as a regeneration treatment,resulting in a preference for edge aggregates instead of isolated retained *** emphasis on site-level retention of biological legacies and forest influence to facilitate re-establishment of mature forest species ensures that ArN coupes achieve the ecological objectives associated with retention ***:Spatial and survey data collected from operational ArN coupes illustrates the development of this silvicultural practice over time and allows comparisons with conventional *** 90%of ArN coupes have met the forest influence target of>50%.The number of ArN coupes harvested per year has varied,but mean retention levels(29%)and the mean area harvested per coupe(24 ha)have remained the *** influence in ArN coupes has decreased over time,as have perimeter-to-area ratios,largely due to a decrease in the number of island *** these measures of complexity have decreased,ArN coupes still have much greater forest influence,retention,and perimeter-to-area ratios when compared to conventional clearfell,burn and sow(CBS)*** observed decrease in boundary complexity should facilitate regeneration burning in ArN coupes,although no increase in the proportion of burnt seedbed was *** proportion of burnt seedbed is strongly correlated with eucalypt seedling stocking and density in ArN coupes,and these attributes were all significantly lower in recent ArN coupes compared to *** differences appear to be due to achieving better burns in recent CBS coupes,rather than poorer ones in ArN cou

关键词： retention forestry Silviculture systems Aggregated retention regeneration burning regeneration success Forest influence eucalyptus

First experience with intracytoplasmic sperm injection for extreme oligozoospermia associated with Crohn's disease and 6-mercaptopurine chemotherapy

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Asian Journal of Andrology 2003年第1期5卷 76-78页

作者： e.scott Sills Michael J.Tucker Division of reproductive endocrinology and Infertility Department of Obstetrics and Gynecology Atlanta Medical Center AtlantaGeorgia 30342USA

Aim: To describe the reproductive outcome following intracytoplasmic sperm injection (ICSI) for male factor infertility associated with Crohn's disease and 6-mercap-topurine (6-MP) chemotherapy. Methods: The male part... 详细信息

ract>Aim: To describe the reproductive outcome following intracytoplasmic sperm injection (ICSI) for male factor infertility associated with Crohn's disease and 6-mercap-topurine (6-MP) chemotherapy. Methods: The male partner of a couple suffered from severe Crohn's disease and received a 3-month course of 6-MP for this condition. Two spontaneous conceptions were established before 6-MP, although post-chemotherapy semen analysis found the sperm concentration to be 8,000/mL. In vitro fertilization (IVF) with ICSI and embryo transfer was performed. results: The woman underwent an uncomplicated controlled ovarian hyperstimulation sequence using a combined rec-FSH+hMG protocol, following late luteal phase pituitary downregulation. This culminated in the retrieval of 18 oocytes, 11 of which were fertilized with ICSI. She later delivered a normal male infant without urogenital anomaly. Four nontransferred blastocysts were cryopreserved. Conclusion: This report describes the first successful birth after ICSI for severe oligozoospermia associated with Crohn's disease and 6-MP therapy. We outline salient features of Crohn's disease, 6-MP pharmacology, and their relevance to human fertility.

关键词： 6-mercaptopurine chemotherapy infertility ICSI