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Universal insertion of molecules in ionic compounds under pressure

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National Science Review 2024年第1期11卷 120-128页

作者： Feng Peng Yanming Ma chris J.Pickard Hanyu Liu Maosheng Miao College of Physics and Electronic Information Luoyang Normal University Department of Chemistry and Biochemistry California State University Northridge State Key Laboratory of Superhard Materials & Key Laboratory of Material Simulation Methods and Software of Ministry of Education College of Physics Jilin University International Center of Future Science Jilin University Department of Materials Science & Metallurgy University of Cambridge Advanced Institute for Materials Research Tohoku University Department of Earth Science University of California Santa Barbara

Using first-principles calculations and crystal structure search methods, we found that many covalently bonded molecules such as H2, N2, CO2, NH3, H2O and CH4may react with NaC l, a prototype ionic solid,and form stable compounds under pressure while retaining their molecular structure. These molecules,despite whether they are homonuclear or heteronuclear, polar or non-polar, small or large, do not show strong chemical interactions with surrounding Na and Cl ions. In contrast, the most stable molecule among all examples, N2, is found to transform into cyclo-N5-anions while reacting with NaC l under high pressures. It provides a new route to synthesize pentazolates, which are promising green energy materials with high energy density. Our work demonstrates a unique and universal hybridization propensity of covalently bonded molecules and solid compounds under pressure. This surprising miscibility suggests possible mixing regions between the molecular and rock layers in the interiors of large planets.

关键词： molecule-solid hybrid materials high-pressure crystal structure prediction density functional theory planet interior

Experimental and analytical investigation on friction resistance force between buried coated pressurized steel pipes and soil

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 615-629页

作者： Shaurav ALAM Tanvir MANZUR John MATTHEWS chris BARTLETT Erez ALLOUCHE Brent KEIL John KRAFT Department of Civil Engineering and Construction Engineering Technology Louisiana Tech UniversityRustonLA 71270USA Department of Civil Engineering Bangladesh University of Engineering and TechnologyDhaka 1000Bangladesh Georgia Tech Research Institute AtlantaGA 30332USA Stantec Inc. Edmonton T5J0K4Canada North West Pipe Company VancouverWA 98684USA

This paper presents an analytical approach for estimating frictional resistance to pipe movement at soil and external pipe surface of buried coated pressurized steel pipes relative to the internal thrust *** proposed analytical method was developed based on 36 experiments,which involved three coating types(cement mortar(CM),polyurethane type-I(PT-I),prefabricated plastic tape(PPT))on pipes’surfaces,three different soils(pea-gravel(PG),sand(S),silty-clay(SC)),and four simulated over burden depths above the pipe’s *** showed frictional resistance decreased with increasing over burden depth above the pipe’s *** degree of frictional resistance at the pipe-soil interface was found to be in the order of PG>SC>S for all coating variations and overburden *** coated pipe buried in all three types of soil produced significantly higher frictional resistance as compared to other coating *** on experimental data,the developed analytical introduced a dimensionless factor“Z”,which included effects of types of coatings,soil,and overburden depths for simplified rapid *** showed that the method provided a better prediction of frictional resistance forces,in comparison to previous analytical methods,which were barely close in predicting friction resistance for different coating variations,soil types,and overburden *** resistance force values reported herein could be considered conservative.

关键词： friction resistance force thrust force coated pressurized steel pipe soil type overburden depth

Predictive modeling for post operative delirium in elderly

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World Journal of Gastrointestinal Oncology 2024年第9期16卷 3761-3764页

作者： chris B Lamprecht Abeer Dagra Brandon.Lucke-Wold Lillian S.Wells Department of Neurosurgery University of FloridaGainevilleFL 32610United States

Delirium,a complex neurocognitive syndrome,frequently emerges following surgery,presenting diverse manifestations and considerable obstacles,especially among the *** editorial delves into the intricate phenomenon of postoperative delirium(POD),shedding light on a study that explores POD in elderly individuals undergoing abdominal malignancy *** study examines pathophysiology and predictive determinants,offering valuable insights into this challenging clinical *** the synthetic minority oversampling technique,a predictive model is developed,incorporating critical risk factors such as comorbidity index,anesthesia grade,and surgical *** is an urgent need for accurate risk factor identification to mitigate POD *** specific to elderly patients with abdominal malignancies,the findings contribute significantly to understanding delirium pathophysiology and *** research is warranted to establish standardized predictive for enhanced generalizability.

关键词： Post-operative delirium Elderly delirium Neurocognitive syndrome Neurotransmitters Abdominal malignancy Predictive model Synthetic minority oversampling technique

Proliferating Satellite Constellations Pose Astronomical and Environmental Challenges

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Engineering 2024年第5期36卷 9-11页

作者： chris Palmer Senior Technology Writer

On 6 October 2023,Amazon(Seattle,WA,USA)launched two prototype satellites into low-Earth orbit[1],the inaugural orbiters of Project Kuiper,a constellation of 3236 satellites that will work together to eventually deliver internet to tens of millions of customers *** Kuiper,named for the belt of ice,rock,and dwarf planets beyond Neptune,is smaller in number than the so-called mega-constellations built by SpaceX(Hawthorne,CA,USA),OneWeb(London.UK),and others,Amazon plans to loft its Kuiper satellites into orbit at a historic pace over the next few years.

关键词： Amazon eventually planet

Unprecedented JWST Observations Contest Cosmological Canons

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Engineering 2024年第6期37卷 6-9页

作者： chris Palmer Senior Technology Writer

After more than 18 months of nearly flawless operation,the James Webb Space Telescope(JWST)continues to deliver amazement,making unexpected discoveries,adding new wrinkles to known phenomena,and calling into question long-held theories of how the universe works.“The instruments are working amazingly well,in essentially all cases better than expected,”said Garth Illingworth,professor emeritus of astronomy and astrophysics at the University of California,Santa Cruz(CA,USA),and one of the three originators of the mission over three decades ago.“It has exceeded every one of its performance requirements,which is truly amazing when you think about how complex it is.”That complexity has included three decades of planning,design,and construction,followed by launch and maneuvering 1.5106 km from Earth to its second Lagrange(L2)orbit,unfolding and locking into position the 18 segments of its 6.5 m diameter main mirror,and deploying 8 motors,90 cables,and some 400 pulleys to unfurl its fragile sunshield[1,2].

关键词： universe Observation Cosmo

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对臭氧层造成破坏的违禁化学物质仍在增加

Engineering 2024年第4期35卷 7-9页

作者： chris Palmer Senior Technology Writer

As reported in a study published in April 2023,some of the globally banned chemicals that decimated the Earth’s ozone layer are still finding their way into the atmosphere[1].While unlikely to greatly impact global ozone levels,the continuing pollution has scientists concerned for two reasons:The chemicals,called chlorofluorocarbons(CFCs),are potent greenhouse gases,and,perhaps more worrying,the sources of the surprising emissions remain unidentified.

关键词： pollution ozone globally

“泰坦”号潜水器--通向死亡的“海洋之门”

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Engineering 2024年第1期32卷 1-3页

作者： chris Palmer Senior Technology Writer

Early on the morning of June 18,2023,far off the shore of Newfoundland,Canada,the Titan deep-sea submersible began its descent into the depths of the North *** was Titan’s inventor and pilot,Stockton Rush,along with four“mission specialists,”several of whom may have paid as much as 250000 USD to accompany Rush on a voyage to the site of the infamous Titanic shipwreck on the ocean *** two hours later.

关键词：泰坦 depths ocean

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NASA激光通信系统创传输速度新纪录

Engineering 2024年第3期34卷 9-11页

作者： chris Palmer Senior Technology Writer

In April 2023,a satellite orbiting approximately 500 km above Earth’s surface delivered terabytes of data at record-breaking rates of up to 200 Gb·s^(-1)—more than 100 times faster than the fastest internet speeds in most cities—via an optical communication link to a ground-based receiver 95 km north of Los Angeles,CA,USA[1].At more than 1000 times faster than the radiofrequency(RF)links traditionally used for satellite communication,this is the highest data rate ever achieved for a space-to-ground optical transmission[1].

关键词：激光通信系统 communication optical

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浮式海上风电助力可再生能源发展

Engineering 2024年第4期35卷 1-3页

作者： chris Palmer Senior Technology Writer

Nearly 150 km off the coast of Norway,in one of the windiest places on Earth,stands Hywind Tampen,the world’s largest floating wind power *** weighing 8800 t and 190 m tall,with roughly one-third of that height sitting below the waterline,Hywind Tampen’s 11 turbines can generate 94.6 MW(Fig.1)[1].The blades—each 80 m long—travel at a blistering 290 km∙h–1,yet because of their size they complete only about 10 to 15 full rotations per minute.A single rotation provides enough electricity to power an average home for a ***,Hywind Tampen,which became fully operational in August 2023,will not power ***,the installation built by energy company Equinor(Stavanger,Norway)will provide 38%of the annual electricity consumed by five nearby offshore oil platforms in the North Sea[1].

关键词： rotation travel floating