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Optical Transient Source AT2021lfa:A Possible“Dirty Fireball”

Research in Astronomy and Astrophysics 2024年第4期24卷 124-133页

作者： Xue-Mei Ye Da-Ming Wei Yi-Ming Zhu Zhi-ping jin Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China National Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China CAS Key Laboratory of Astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China

AT2021lfa,also known as ZTF21aayokph,was detected by the Zwicky Transient Facility on 2021 May 4,a 05:34:48 ***-up observations were conducted using a range of ground-based optical telescopes,as wel as Swift/XRT and VLA ***2021lfa is classified as an“orphan afterglow”candidate due to its rapid flux decline and its reddened color(g-r=0.17±0.14 mag).For an optical transient source without promp gamma-ray detection,one key point is to determine its burst *** we measure the burst time through fitting the initial bump feature of AT2021lfa and obtain its burst time as 2021 May 3,at 22:09:50 *** afterglowpy,we model the multi-band afterglow of AT2021lfa and find that the standard model canno reproduce the late radio observations *** that the microphysical parameters ε_(e),ε_(B)(the energy fraction given to electrons and magnetic field),andξN(the fraction of accelerated electrons)may vary with time we then model the afterglow of AT2021lfa taking into account the temporal evolution of the physical parameters ε_(e),ε^(B),and ξ_(N) and find in this case the multi-wavelength observations can be reproduced *** initial Lorentz factor of AT2021lfa can be estimated from the peak time of the early afterglow,which yields a value of about 18 suggesting that AT2021lfa should be classified as a“dirty fireball.”From the upper limit for the prompt emission energy of AT2021lfa,we obtain that the radiation efficiency is less than 0.02%,which is much smaller than that of ordinary gamma-ray bursts(GRBs).It is also interesting that the fitted values of jet angle and viewing angle are very large,θ_(c)~0.66 rad,θ_(v)~0.53 rad,which may lead to the low Lorentz factor and radiation *** compared with GRB afterglow samples,it is evident that the onset bump timescale of AT2021lfa satisfies the empirical relationships observed in GRB ***,the luminosity of AT2021lfa falls within the range of observations for GRB samples;howeve

关键词： gamma-rays:ISM methods:numerical radiation mechanisms:non-thermal

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A deoxidation thermodynamic model for 304 stainless steel considering multiple-components coupled reactions

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Journal of Iron and Steel Research(International) 2024年第1期31卷 74-91页

作者： Yan Yan Guang-hao Shang li-ping Zhang Shao-ying li Han-jie Guo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing100083China Henan jinhui Stainless Steel Industry Group Co. Ltd.Xuchang461500HenanChina Changge jinhui Recycling Metal R&D Co. Ltd.Xuchang461500HenanChina

A thermodynamic model for predicting the equilibrium oxygens of 304 stainless steel was developed based on the theory of slag-steel equilibrium,the law of mass conservation,and the ion and molecule coexistence *** the developed model,the Fe-Cr-Mn-Si-Al-S-O-melts reaction system and CaO-MgO-CaF_(2)-FeO-MnO-Al_(2)O_(3)-SiO_(2)-Cr2O_(3)slags were *** oxygen contents calculated by the model are in good agreement with experimental results and reference *** equilibrium oxygen contents in 304 stainless steel mainly decrease with increasing binary basicity(w(CaO)/w(SiO_(2)),where w(i)is the mass percentage of component i)and decreasing *** binary basicity at 2.0 while maintaining temperatures lower than 1823 K will keep the oxygen contents in the 304 stainless steel lower than 15×10^(-6).The equilibrium oxygen contents may also be decreased with increasing content of MgO in slags,which is more significant at lower binary ***,a small amount of FeO,MnO,and Al_(2)O_(3)(about 0-2.5 wt.%)in slags has little effect on equilibrium oxygen ***,it is found that the[C]-[O]reaction may occur during refining process but will not significantly affect the equilibrium oxygen contents.

关键词： Complex deoxidation Thermodynamic model Ion and molecule coexistence theory 304 stainless steel Slag-steel reaction

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Spleen volume is associated with overt hepatic encephalopathy after transjugular intrahepatic portosystemic shunt in patients with portal hypertension

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World Journal of Gastrointestinal Surgery 2024年第7期16卷 2054-2064页

作者： Chun-Juan Zhao Chao Ren Zhen Yuan Guo-Hui Bai jin-Yu li Long Gao jin-Hui li Ze-Qi Duan Dui-ping Feng Hui Zhang College of Medical Imaging Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Radiology The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Occupational Health School of Public HealthShanxi Key Laboratory of Environmental Health Impairment and PreventionNHC Key Laboratory of PneumoconiosisMOE Key Laboratory of Coal Environmental Pathogenicity and PreventionShanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Oncological and Vascular Intervention The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Shanxi Provincial Clinical Research Center for Interventional Medicine The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina First Clinical Medical College Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Shanxi Key Laboratory of Intelligent Imaging and Nanomedicine The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Intelligent Imaging Big Data and Functional Nano-imaging Engineering Research Center of Shanxi Province The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina

BACKGROUND Portal shunt and immune status related to the spleen are related to the occurrence of hepatic encephalopathy(HE).It is unknown whether spleen volume before transjugular intrahepatic portosystemic shunt(TIPS)is related to postoperative *** To investigate the relationship between spleen volume and the occurrence of *** This study included 135 patients with liver cirrhosis who underwent TIPS,and liver and spleen volumes were elevated upon computed tomography *** Kaplan-Meier curve was used to compare the difference in the incidence rate of HE among patients with different spleen *** and multivariate Cox regression analyses were performed to identify the factors affecting overt HE(OHE).Restricted cubic spline was used to examine the shapes of the dose-response association between spleen volumes and OHE *** The results showed that 37(27.2%)of 135 patients experienced OHE during a 1-year follow-up *** with preoperative spleen volume(901.30±471.90 cm3),there was a significant decrease in spleen volume after TIPS(697.60±281.0 cm^(3))in OHE *** the severity of OHE increased,the spleen volume significantly decreased(Pline model showed that with an increasing spleen volume,OHE risk showed an initial increase and then decrease(P<0.05).CONCLUSION Spleen volume is related to the occurrence of OHE after *** spleen volume is an independent risk factor for post-TIPS OHE.

关键词： Hepatic encephalopathy Transjugular intrahepatic portosystemic shunt Spleen volume Portal hypertension Cirrhosis

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Comprehensive insights:unraveling the mechanisms of gut commensals in glucose metabolism regulation

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Science China(life Sciences) 2024年第2期67卷 414-417页

作者： Zhipeng li Qixing Nie Shao-ping Nie State Key Laboratory of Food Science and Resources China-Canada Joint Lab of Food Science and Technology(Nanchang)Key Laboratory of Bioactive Polysaccharides of Jiangxi ProvinceNanchang UniversityNanchang 330047China

The prevalence of type 2 diabetes(T2D)has escalated to a global epidemic,garnering widespread *** research utilizing germ-free(GF)mice,antibiotic treatments,and fecal microbiota transplantation approaches has established the critical role of gut microbiota in modulating glucose *** microbiota interacts with diets and the mucosal immune system,influencing intestinal permeability and the penetration of microbial products.

关键词： metabolism utilizing insight

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Single-Cell RNA Expression Profiling of ACE2 and AXL in the Human Maternal-Fetal Interface

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Reproductive and Developmental Medicine 2020年第1期4卷 7-10页

作者： Qing-liang Zheng Tao Duan li-ping jin Clinical and Translational Research Center Shanghai First Maternity and Infant HospitalTongji University School of MedicineShanghai 201204China

2019 novel coronavirus disease has resulted in thousands of critically ill patients in China,which is a serious threat to people’s life and *** acute respiratory syndrome-coronavirus 2(SARS-CoV-2)was reported to share the same receptor,angiotensin-converting enzyme 2(ACE2),with ***,based on the public single-cell RNA-sequencing database,we analyzed the mRNA expression profile of putative receptor ACE2 and AXL receptor tyrosine kinase(AXL)in the early maternal-fetal *** result indicates that the ACE2 has very low expression in the different cell types of early maternal-fetal interface,except slightly high in decidual perivascular cells cluster 1(PV1).Interestingly,we found that the Zika virus(ZIKV)receptor AXL expression is concentrated in perivascular cells and stromal cells,indicating that there are relatively more AXL-expressing cells in the early maternal-fetal *** study provides a possible infection route and mechanism for the SARS-CoV-2-or ZIKV-infected mother-to-fetus transmission disease,which could be informative for future therapeutic strategy development.

关键词： 2019 Novel Coronavirus Disease ACE2 AXL Maternal-Fetal Interface Severe Acute Respiratory Syndrome Coronavirus 2 Vertical Transmission

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Priority effects of forbs arriving early:the role of root interaction and asymmetric competition

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Ecological Processes 2024年第1期13卷 53-65页

作者： Xiaohong Yan Xiliang li Ke jin Institute of Grassland Research Chinese Academy of Agricultural Sciences

Background The priority effect of plant arrival is a key driver of community assembly and ecosystem succession during the restoration of degraded plant communities. However, the significance of the arrival order of different plant functional groups and their interactions with community assemblies remains unclear. Using a phytotron experiment with three fully crossed factors, we investigated the underlying mechanisms of priority effects and their relationships with the biomass and biodiversity effects in mixed plant communities by manipulating the order of arrival of species, isolation of roots, and removal of specific *** The results showed that the strength and direction of priority effects were influenced by arrival order, root interactions, asymmetric competition among species, and their interactions. The identities of early and late-sown species also determined the magnitude of priority effects. The priority effects were stronger in grass-first(24.76%) and legume-first communities(24.48%) than in forb-first communities. The pot biomass of the different priority treatments was highest in grass-first(5.85 g), followed by legume-first(3.94 g) and forb-first(2.48 g). The order of arrival in the mixture significantly affected the net biodiversity effects(P lies. In addition, the importance of the priority effect of forbs sown first is related to community assembly, which may be a key determinant in successfully establishing a highly diverse community in the early stages of restoration. Species with weak competition should be considered in the early stage of community ass

关键词： Community assembly Order of arrival Overyielding Plant functional group Root isolation

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Effect of nitrile butadiene rubber hardness on the sealing characteristics of hydraulic O-ring rod seals

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第1期25卷 63-78页

作者： Xiaoxuan li Bingqing WANG Xudong PENG Yuntang li Xiaolu li Yuan CHEN Jie jin College of Quality and Safety Engineering China Jiliang UniversityHangzhou310018China College of Mechanical and Electrical Engineering China Jiliang UniversityHangzhou310018China College of Mechanical Engineering Zhejiang University of TechnologyHangzhou310023China

The nitrile butadiene rubber(NBR)hardness effect on the sealing characteristics of hydraulic O-ring rod seals is analyzed based on a mixed lubrication elastohydrodynamic *** studies are conducted to reveal the mechanism of the influence of rubber hardness on the static and dynamic behavior of *** optimized selections of rubber hardness are then investigated under different *** show that the low hardness seal is prone to stress concentration due to the extrusion effect under high pressure conditions;it is also more prone to leaking.A high hardness seal can better prevent leakage by reducing film thickness but it will cause large frictional power loss and increase the probability of wear *** choice of low hardness is recommended to reduce friction with the premise that leakage requirements are met.

关键词： Nitrile butadiene rubber(NBR)hardness Sealing characteristics Optimized selection O-ring seal

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Constructing long-cycling crystalline C_(3)N_(4)-based carbonaceous anodes for sodium-ion battery via N configuration control

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Carbon Energy 2024年第1期6卷 159-171页

作者： Ying Wang Hongguan li Shuanlong Di Boyin Zhai ping Niu Antonios Kelarakis Shulan Wang li li School of Metallurgy Northeastern UniversityShenyangLiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyangLiaoningChina Department of Chemistry College of ScienceNortheastern UniversityShenyangLiaoningChina School of Natural Sciences UCLan Research Centre for Smart MaterialsUniversity of Central LancashirePrestonUK Foshan Graduate School of Innovation Northeastern UniversityFoshanGuangdongChina

Carbon nitrides with two-dimensional layered structures and high theoretical capacities are attractive as anode materials for sodium-ion batteries while their low crystallinity and insufficient structural stability strongly restrict their practical *** carbon nitrides with conductive carbon may relieve these ***,little is known about the influence of nitrogen(N)configurations on the interactions between carbon and C_(3)N_(4),which is fundamentally critical for guiding the precise design of advanced C_(3)N_(4)-related ***,highly crystalline C_(3)N_(4)(poly(triazine imide),PTI)based all-carbon composites were developed by molten salt *** importantly,the vital role of pyrrolic-N for enhancing charge transfer and boosting Na+storage of C_(3)N_(4)-based composites,which was confirmed by both theoretical and experimental evidence,was spot-highlighted for the first *** elaborately controlling the salt composition,the composite with high pyrrolic-N and minimized graphitic-N content was *** from the formation of highly crystalline PTI and electrochemically favorable pyrrolic-N configurations,the composite delivered an unusual reverse growth and record-level cycling stability even after 5000 cycles along with high reversible capacity and outstanding full-cell capacity *** work broadens the energy storage applications of C_(3)N_(4) and provides new prospects for the design of advanced all-carbon electrodes.

关键词： anode highly crystalline C_(3)N_(4) N configuration sodium-ion batteries ultra-long cyclic stability

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Unveiling the size effect of nitrogen-doped carbon-supported copper-based catalysts on nitrate-to-ammonia electroreduction

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Nano Research 2024年第4期17卷 2438-2443页

作者： Ran li Taotao Gao Wenxi Qiu Minghao Xie Zhaoyu jin Panpan li College of Materials Science and Engineering Sichuan UniversityChengdu 610065China Institute for Advanced Study Chengdu UniversityChengdu 610106China Materials Science and Engineering Program and Walker Department of Mechanical Engineering The University of Texas at AustinAustinTexas 78712USA Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China

The electrocatalytic nitrate reduction reaction(NitRR)represents a promising approach toward achieving economically and environmentally sustainable ***,it remains a challenge to regulate the size effect of electrocatalysts to optimize the catalytic activity and ammonia ***,the Cu-based catalysts were tailored at the atomic level to exhibit a size gradient ranging from single-atom catalysts(SACs,0.15–0.35 nm)to single-cluster catalysts(SCCs,1.0–2.8 nm)and nanoparticles(NPs,20–30 nm),with the aim of studying the size effect for the NO_(3)^(-)-to-NH_(3) reduction ***,the Cu SCCs exhibit enhanced metal–substrate and metal–metal interactions by taking advantageous features of Cu SACs and Cu ***,Cu SCCs achieve exceptional electrocatalytic performance for the NitRR with a maximum Faradaic efficiency of ca.96%NH_(3)and the largest yield rate of ca.1.99 mg·h^(-1)·cm^(-2) at-0.5 V *** hydrogen electrode(RHE).The theoretical calculation further reveals the size effect and coordination environment on the high catalytic activity and selectivity for the *** work provides a promising various size-controlled design strategy for aerogel-based catalysts effectively applied in various electrocatalytic reactions.

关键词： nitrate electroreduction ammonia electrosynthesis size effect single-cluster catalyst

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Effects of inorganic nutrients and environmental factors on the removal of n-propylbenzene and isopropylbenzene in seawater by cryptophytes Rhinomonas reticulata S6A

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Journal of Oceanology and limnology 2024年第4期42卷 1200-1215页

作者： Jiali CUI Shuhao DU Yumei li Haiping li ping ZHANG Fanping MENG Key Laboratory of Marine Environment and Ecology Ministry of EducationOcean University of ChinaQingdao 266100China College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China

To effectively remove n-propylbenzene(n-PBZ)and isopropylbenzene(i-PBZ)leaked into seawater using Rhinomonas reticulata S 6 A(a newly isolated marine microalga),the effects of three inorganic nutrients and four environmental factors on their degradation were determined after 7 d of *** show that NaNO_(3) at 300 mg/L caused a higher removal efficiency of both n-PBZ and i-PBZ(44.79%and 39.26%),while for NaH_(2) PO_(4)·H_(2) O,greater removal rates of two PBZs(47.30%and 42.23%)were achieved at 30 and 20 mg/L,***_(3) supplementation(500-750 mg/L)resulted in a large reduction(43.67%-45.04%)in i-PBZ *** change in seawater pH(from 6 to 9)did not affect the elimination of n-PBZ and *** most suitable salinity and temperature were 30 and 25-30℃,respectively,leading to the PBZs removal of~40%.light intensity exhibited significant influence on elimination of PBZs,and the maximum removal efficiencies of 56.07%(n-PBZ)and 55.00%(i-PBZ)were recorded under 200 and 600μmol/(m^(2)·s),*** addition,the microalga could still remove PBZs when it failed to grow well due to darkness,strong light,low temperature,or low salinity,which might mean that good growth of alga is not always a necessary condition for PBZs ***,attention should be paid to the suitability of nutrient levels and environmental conditions(excluding pH)in seawater when using microalgae for bioremediating PBZs-contaminated seawater.

关键词： propylbenzene(PBZ) Rhinomonas reticulata seawater inorganic nutrient environmental factor

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