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Increasing Threat of Scarcity Prompts Rise in Water Recycling

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Engineering 2024年第2期33卷 6-8页

作者： chris Palmer Senior Technology Writer

In January 2018,construction wrapped on Salesforce Tower(Fig.1),a 61-story office building that now dominates the skyline of San Francisco,CA,*** addition to being the tallest building in the city,Salesforce Tower is the largest structure in the world with an onsite water recycling *** by the Australian com-pany Aquacell(Milton,NSW,Australia),the system cleans 113 m^(3)of sewage,sink,shower,and other wastewater each day for use in irrigation and flushing toilets,saving an estimated 35000 m?of water anmually[1].The building is just one of dozens in San Fran-cisco outitted with their own water recycling systems,thanks to a city mandate enacted in 2015[1].

关键词： cycling wastewater recycling

Attitude control of multi-spacecraft systems on SO(3)with stochastic links failure

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Chinese Journal of Aeronautics 2024年第3期37卷 320-331页

作者： KANG Zeyu SHEN Qiang WU Shufan chris J.DAMAREN MU Zhongcheng School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China Institute for Aerospace Studies University of TorontoTorontoOntario M3H 5T6Canada

In this paper,for Multi-Spacecraft System(MSS)with a directed communication topology link and a static virtual leader,a controller is proposed to realize attitude consensus and attitude stabilization with stochastic links failure and actuator ***,an MSS attitude error model suitable for a directed topology link and with a static virtual leader based on SO(3)is derived,which considers that the attitude error on SO(3)cannot be defined based on algebraic ***,we design a controller to realize the MSS on SO(3)with attitude consensus and attitude stabilization under stochastic links failure and actuator ***,the simulation results of a multi-spacecraft system with stochastic links failure and a static virtual leader spacecraft are demonstrated to illustrate the efficiency of the attitude controller.

关键词： Multi-spacecraft systems Attitude consensus Attitude stabilization Stochastic links failure Super-martingale convergence

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

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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

“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

Gastroesophageal signet ring cell carcinoma morbidity and mortality: A retrospective review

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World Journal of Gastrointestinal Surgery 2024年第6期16卷 1629-1636页

作者： Megan Grinlinton chris Furkert Andrew Maurice Neville Angelo Michael Booth Department of General Surgery North Shore HospitalAuckland 0620New Zealand Department of Pathology North Shore HospitalAuckland 0620New Zealand

BACKGROUND Upper gastrointestinal(GI)signet ring cell carcinomas(SRCC)confer a poor *** benefit of operative intervention for this patient group is contro-versial in terms of overall *** To investigate factors relating to survival in patients with upper GI *** A retrospective,tertiary,single-centre review of patients who were diagnosed with oesophageal,gastroesophageal junction and gastric SRCC was *** primary outcome was to compare mortality of patients who underwent operative management with those who had nonoperative ***-dary outcomes included assessing the relationship between demographic and histopathological factors,and *** One hundred and thirty-one patients were *** one-year survival for the operative group was 81%and for the nonoperative group was 19.1%.The five-year survival in the operative group was 28.6%vs 1.5%in the nonoperative *** difference in overall survival between groups was statistically significant(HR 0.19,95%CI(0.13-0.30),P<0.001).There was no difference in survival when ad-justing for age,smoking status or *** multivariate analysis,patients who underwent surgical management,those with a lower stage of disease,and those with a lower Charlson Comorbidity Index(CCI)had significantly improved *** Well-selected patients with upper GI SRCC appear to have reasonable medium-term survival following *** surgery to a carefully selected patient group may improve the outcome for this disease.

关键词： Signet ring cell carcinoma Gastric cancer Oesophageal cancer Poorly cohesive gastric cancer Diffuse gastric cancer

Eco-evolutionary evidence for the global diversity pattern of Cycas(Cycadaceae)

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Journal of Integrative Plant Biology 2024年第6期66卷 1170-1191页

作者： Jian Liu Anders JLindstrom Yiqing Gong Shanshan Dong Yusheng(chris)Liu Shouzhou Zhang Xun Gong CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China Department of Economic Plants and Biotechnology Yunnan Key Laboratory for Wild Plant ResourcesKunming Institute of BotanyChinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China Global Biodiversity Conservancy 144/124 Moo3Soi Bua ThongBangsalaeSattahipChonburi 20250Thailand Key Laboratory of Southern Subtropical Plant Diversity Fairy Lake Botanical GardenShenzhen&Chinese Academy of SciencesShenzhen 518004China Department of Earth and Environmental Sciences Indiana University-IndianapolisIndianapolisIN 46202USA

The evolution of the latitudinal diversity gradient(LDG),characterized by a peak in diversity toward the tropics,has captured significant attention in evolutionary biology and ***,the inverse LDG(i-LDG)mechanism,wherein species richness increases toward the poles,remains inadequately *** are among one of the oldest lineages of extant seed plants and have undergone extensive diversification in the ***,the extant cycad abundance exhibits an i-LDG pattern,and the underlying causes for this phenomenon remain largely ***,using 1,843 nuclear genes from a nearly complete sampling,we conducted comprehensive phylogenomic analyses to establish a robust species-level phylogeny for Cycas,the largest genus within *** then reconstructed the spatial-temporal dynamics and integrated global environmental data to evaluate the roles of species ages,diversification rates,contemporary environment,and conservatism to ancestral niches in shaping the i-LDG *** found Cycas experienced decreased diversification rates,coupled with the cooling temperature since its origin in the Eocene from continental *** regions have distinctively contributed to the formation of i-LDG for Cycas,with the northern hemisphere acting as evolutionary museums and the southern hemisphere serving as ***,water-related climate variables,specifically precipitation seasonality and potential evapotranspiration,were identified as paramount factors constraining Cycas species richness in the rainforest biome near the ***,the adherence to ancestral monsoonal climates emerges as a critical factor in sustaining the diversity *** study underscores the imperative of integrating both evolutionary and ecological approaches to comprehensively unravel the mechanisms underpinning global biodiversity patterns.

关键词： cycads latitudinal diversity gradient niche conservatism spatiotemporal diversification species richness

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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