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An extended numerical model of the first exothermic peak for three dimensional printed cement-based materials

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 80-88页

作者： Wei JIANG Wenqian li xi CHEN School of Materials Science and Engineering Tongji UniversityShanghai 200092China School of Civil Engineering Tongji UniversityShanghai 200092China

The first exothermic peak of cement-based material occurs a few minutes after mixing,and the properties of three dimensional(3D)printed concrete,such as setting time,are very sensitive to *** this background,based on the classical Park cement exothermic model of hydration,we propose and construct a numerical model of the first exothermic peak,taking into account the proportions of C_(3)S,C_(3)A and quicklime in *** calculated parameters are calibrated by means of relevant published exothermic test *** is found that this developed model offers a good simulation of the first exothermic peak of hydration for C_(3)S and C_(3)A proportions from 0 to 100% of cement clinker and reflects the effect of quicklime content at 8%-10%.The unique value of this research is provision of an important computational tool for applications that are sensitive to the first exothermic peak of hydration,such as 3D printing.

关键词： 3D printed cement-based materials cement hydration the first exothermic peak liquid quick-setting agent numerical model

Genesis of ultra-deep dolostone and controlling factors of largescale reservoir:A case study of the Sinian Dengying Formation and the Cambrian Longwangmiao Formation in the Sichuan Basin

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Science China Earth Sciences 2024年第7期67卷 2352-2382页

作者： xi li Guangyou ZHU Zhiyao ZHANG PetroChina Research Institute of Petroleum Exploration and Development Beijing 100083China School of Geosciences Yangtze UniversityWuhan 430100China School of Earth Resoures China University of GeosciencesWuhan 430074China

This paper investigates the origin of ultra-deep dolostone and the factors influencing large-scale dolostone reservoirs,focusing on the Sinian Dengying Formation and the Cambrian Longwangmiao Formation in the Sichuan *** study involves petrology,microscale X-ray diffraction,trace element analysis,and C-O-Sr-Mg isotope experiments to provide a detailed *** research findings indicate that the Dengying and Longwangmiao formations comprise six types of matrix dolostone and four types of *** Dengying Formation,which developed under a sedimentary background of a restricted platform,contains special microbial and microcrystalline *** dolomite grains are small(line,and calcite dolostones with coarser and more ordered crystals exhibit similar δ^(13)C and^(87)Sr/^(86)Sr values to microbial and microcrystalline *** the sedimentary period of the Dengying Formation,ancient marine conditions were favorable for microbial *** induced the direct precipitation of primary dolomite in seawater,forming microbial and microcrystalline dolostones during the seawater diagenesis *** the subsequent diagenesis period,dolostones underwent the effects of dissolution-recrystallization,structures,and hydrothermal *** resulted in the formation of dolostone with coarser crystals,a higher degree of order,and various types of *** Longwangmiao Formation was developed in an interplatform beach characterized by special particle *** particle dolostone has a large grain size(>30μm),high order degree(Min=0.7),small unit cell parameters,high Na content

关键词： Ultra-deep layers Dolostone Supercontinent evolution Microscale geochemistry Dengying Formation Longwangmiao Formation Sichuan Basin

A_(2)B_(7)-type La-Mg-Ni alloys prepared by Mg thermal diffusion for improved hydrogen storage performance

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Rare Metals 2024年第7期43卷 3260-3272页

作者： Yong-xi Zhang Guan-Jiu Wu Jing Gu Hong-xing Kang Yuan li Di Zhou Wen-Feng Wang Lu Zhang shu-Min Han Hebei Key Laboratory of Applied Chemistry School of Environmental and Chemical EngineeringYanshan UniversityQinhuangdao 066004China Department of Chemistry and Biochemistry San Diego State UniversitySan DiegoCA92182-1030USA State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

A novel approach based on thermal diffusion was used to achieve controllable Mg content in A_(2)B_(7)-type La-Mg-Ni-based *** formation mechanism of the A_(2)B_(7)-type phase as a result of the thermal diffusion process and the effect of Mg content on hydrogen storage performance were investigated.X-ray diffraction(XRD)patterns and Rietveld refinement results showed that increased Mg transformed the LaNi_(5)phase in the La_(0.74)Sm_(0.03)Y_(0.23)Ni_(4.32)Al_(0.04)precursor alloy into a superlattice *** electron microscopy(SEM)images showed that Mg was evenly distributed in the alloy *** in the superlattice significantly inhibited the phase decomposition of the superlattice structure during the hydrogen absorption/desorption *** A_(2)B_(7)-type La_(0.57)Sm_(0.02)Y_(0.18)Mg_(0.23)Ni_(3.38)Al_(0.03)alloy composed of Gd_(2)Co_(7)and Ce_(2)Ni_(7)phases was successfully *** pressure-composition isotherm profiles showed that the alloy had a hydrogen storage capacity as high as 1.73 wt%,with good cycling *** 50 cycles of hydrogen absorption/desorption,the alloy retained a hydrogen storage capacity of 1.45 wt%,with a capacity retention rate of up to 84.28%.The Mg thermal diffusion process thus provides a new approach for the controlled preparation of La-Mg-Ni-based alloys.

关键词： La-Mg-Ni-based hydrogen storage alloy A_(2)B_(7)-type superlattice alloy Mg thermal diffusion process Phase transformation Hydrogen storage property

A comparative study of three concentrations of intravenous nalbuphine combined with hydromorphone for post-cesarean delivery analgesia

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Chinese Medical Journal 2020年第5期133卷 523-529页

作者： Chun-Yun Huang shu-xi li Mei-Juan Yang li-li Xu xin-Zhong Chen Department of Anesthesia Women’s HospitalZhejiang University School of MedicineHangzhouZhejiang 310006China

Background:Nalbuphine has been suggested to be used for post-cesarean section(CS)intravenous ***,ideal concentration of nalbuphine for such analgesia remains *** present study was conducted to explore an ideal concentration of nalbuphine for post-CS intravenous analgesia by evaluating the analgesic effects and side-effects of three different concentrations of nalbuphine combined with hydromorphone for post-CS intravenous analgesia in healthy ***:One-hundred-and-fourteen parturients undergoing elective CS were randomly allocated to one of three groups(38 subjects per group)according to an Excel-generated random number sheet to receive hydromorphone 0.05 mg/mL+nalbuphine 0.5 mg/mL(group LN),hydromorphone 0.05 mg/mL+nalbuphine 0.7 mg/mL(group MN),and hydromorphone 0.05 mg/mL+nalbuphine 0.9 mg/mL(group HN)using patient-controlled analgesia(PCA)*** analog scale(VAS)for pain,PCA bolus demands,cumulative PCA dose,satisfaction score,Ramsay score,and side-effects such as urinary retention were ***:The number of PCA bolus demands and cumulative PCA dose during the first 48 h after CS were significantly higher in group LN(21±16 bolus,129±25 mL)than those in group MN(15±10 bolus,120±16 mL)(both P0.05).VAS scores were significantly lower in group HN than those in group MN and group LN for uterine cramping pain at rest and after breast-feeding within 12 h after CS(all P0.05).Ramsay sedation scale score in groupHNwas significantly higher than that in group MN at 8 and 12 h after CS(all P<0.01)and group LN at 4,8,12,24 h after CS(all P<0.05).Conclusions

关键词： Hydromorphone Nalbuphine Cesarean section Post-operative analgesia Patient-controlled intravenous analgesia

A new method to solve the Reynolds equation including mass-conserving cavitation by physics informed neural networks(PINNs)with both soft and hard constraints

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Friction 2024年第6期12卷 1165-1175页

作者： Yinhu xi Jinhui DENG Yiling li School of Mechanical Engineering Anhui University of Science and TechnologyHuainan 232001China Ericsson AB Datalinjen 3Linköping 58330Sweden

In this work,a new method to solve the Reynolds equation including mass-conserving cavitation by using the physics informed neural networks(PINNs)is *** complementarity relationship between the pressure and the void fraction is *** are several difficulties in problem solving,and the solutions are ***,the difficulty for considering the pressure inequality constraint by PINNs is solved by transferring it into one equality constraint without introducing *** the void fraction inequality constraint is considered by using the hard constraint with the max-min ***,to avoid the fluctuation of the boundary value problems,the hard constraint method is also utilized to apply the boundary pressure values and the corresponding functions are ***,for avoiding the trivial solution the limitation for the mean value of the void fraction is *** results are validated against existing data,and both the incompressible and compressible lubricant are *** agreement can be found for both the domain and domain boundaries.

关键词： Reynolds equation mass-conserving cavitation physics informed neural networks hard constraints trivial solution

Photosynthetic response dynamics in the invasive species Tithonia diversifolia and two co-occurring native shrub species under fluctuating light conditions

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Plant Diversity 2024年第2期46卷 265-273页

作者： Ju li shu-Bin Zhang Yang-Ping li CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglunMengla 666303YunnanChina University of Chinese Academy of Sciences Beijing 100049China

To determine the invasiveness of invasive plants,many studies have compared photosynthetic traits or strategies between invasive and native ***,few studies have compared the photosynthetic dynamics between invasive and native species during light *** compared photosynthetic induction,relaxation dynamics and leaf traits between the invasive species,Tithonia diversifolia and two native species,Clerodendrum bungei and Blumea balsamifera,in full-sun and shady *** photosynthetic dynamics and leaf traits differed among *** showed a slower induction speed and stomatal opening response but had higher average intrinsic water-use efficiency than the two native species in full-sun ***,the slow induction response may be attributed to the longer stomatal length in *** had a significant effect on photosynthetic dynamics in *** and *** but not in *** shady habitat,*** had a faster photosynthetic induction response than in full-sun habitat,leading to a higher average stomatal conductance during photosynthetic induction in *** than in the two native *** contrast,*** had a larger stomatal length and slower photosynthetic induction and relaxation response in shady habitat than in full-sun habitat,resulting in higher carbon gain during photosynthetic ***,in both habitats,*** had an overall higher carbon gain during light fluctuations than the two native *** results indicated that *** can adopt more effective response strategies under fluctuating light environments to maximize carbon gain,which may contribute to its successful invasion.

关键词： Invasive plant Photosynthetic induction Photosynthetic relaxation Carbon gain Stomatal traits Tithonia diversifolia

Preface to the Special Issue in Celebration of Professor Shouwen Yu’s 85th Birthday

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Acta Mechanica Solida Sinica 2024年第3期37卷 361-362页

作者： xi-Qiao Feng Qunyang li Department of Engineering Mechanics Tsinghua UniversityBeijing100084China

Shouwen Yu,Emeritus Professor of Applied Mechanics at Tsinghua University,was born on May 4,1939 in xianyou County,Fujian Province,*** pursued his undergraduate studies from 1955 to 1958 in the Department of Civil Str... 详细信息

关键词： Fujian Preface pursue

Machine Learning-based Identification of Contaminated Images in light Curve Data Preprocessing

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Research in Astronomy and Astrophysics 2024年第4期24卷 287-295页

作者： Hui li Rong-Wang li Peng shu Yu-Qiang li Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Space Object and Debris Observation Chinese Academy of SciencesNanjing 210023China

Attitude is one of the crucial parameters for space objects and plays a vital role in collision prediction and debris *** light curves to determine attitude is the most commonly used *** photometric observations,outliers may exist in the obtained light curves due to various ***,preprocessing is required to remove these outliers to obtain high quality light *** statistical analysis,the reasons leading to outliers can be categorized into two main types:first,the brightness of the object significantly increases due to the passage of a star nearby,referred to as“stellar contamination,”and second,the brightness markedly decreases due to cloudy cover,referred to as“cloudy contamination.”The traditional approach of manually inspecting images for contamination is time-consuming and ***,we propose the utilization of machine learning methods as a *** Neural Networks and SVMs are employed to identify cases of stellar contamination and cloudy contamination,achieving F1 scores of 1.00 and 0.98 on a test set,*** also explore other machine learning methods such as ResNet-18 and light Gradient Boosting Machine,then conduct comparative analyses of the results.

关键词： techniques:image processing methods:data analysis light pollution

Indian monsoon drove the dispersal of the thoracica group of Scytodes spitting spiders

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Zoological Research 2024年第1期45卷 152-159页

作者： Yu-Fa Luo shu-Qiang li School of life and Environmental Sciences Shaoxing UniversityShaoxingZhejiang 312000China Key Laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of SciencesBeijing 100101China Southeast Asia Biodiversity Research Institute Chinese Academy of SciencesYezinNay Pyi Taw 05282Myanmar

We examined the global biogeography of the Scytodes thoracica group of spitting spiders based on 23 years of sampling at the species level(61 species in the thoracica group and 84 species of Scytodes)using DNA data from six *** results indicated that the thoracica group initially dispersed from Southeast Asia to East Africa between 46.5 and 33.0 million years ago,and dispersal events intensified between Southeast/South Asia and East/South Africa from the early to late *** timing of these events indicates that Asian-African faunal exchange of the thoracica group was driven by the Indian monsoon,and the pattern of dispersal suggests that colonialization took root when the Indian monsoon shifted from a North-South direction to an East-West direction from the middle Eocene.

关键词： Geological event Climate change Ballooning organism Faunal exchange Species distribution