检索结果-南通市图书馆

Geochemical characteristics of the Permian marine mudstone and constraints on its provenance and paleoenvironment in the fenghai area,Fujian Province, southeastern China

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2019年第3期16卷 527-540页

作者： Qi-feng Xie yuan-feng Cai Yun-Peng Dong Ming-Guo Zhai Dun-Peng Li State Key Laboratory of Continental Dynamics Northwest University Xi’an 710069 ShaanxiChina College of Zijin Mining Fuzhou University Fuzhou 350108 FujianChina State Key Laboratory for Mineral Deposits Research Nanjing University Nanjing 210046 JiangsuChina Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029China

Permian marine strata have gradually become a research focus in the *** marine strata of the Late Permian Dalong Formation(P3d)in the fenghai area,Fujian Province,have become more and more important as their geochemical characteristics record important geological information and are a good indicator for recovering and reconstructing the paleosedimentary environments and tectonic *** major elements,trace elements and rare earth elements were analyzed by XRF and ICP-MS,*** on the results of detailed field geological surveys,profile measurements as well as typical sample collection,the tectonic setting and provenance of Permian marine mudstone were comprehensively *** results showed that the Dalong Formation(P3d)was deposited in an active continental margin tectonic environment as revealed by the relation between Fe2O3 + MgO and TiO2 and Al2O3/*** fingerprint characteristics of Mn,Fe,Co,Ni and REE and the ratio of U/Th,V/Cr,Sr/Ba,(La/Yb)N and V/(V +Ni)indicated that the sedimentary provenance was mainly derived from potassium feldspar,followed by *** water bodies showed a gradually decreasing depositional rate trend,water depth gradually shallowing and paleo-salinity and productivity gradually ***,since transient delamination occurred during sedimentary processes,sedimentary water bodies showed obvious neritic *** was consistent with the results revealed by lithological and geochemical *** mudstone and siltstone transitioned into fine sandstone from bottom to top,indicating paleo-water bodies became *** research results provided good reference and guidance for understanding Permian paleo-sedimentary environments and tectonic attributes of the Yong’an area,Fujian Province,southeastern China.

关键词： Late Permian Dalong Formation Geochemistry Sedimentary characteristic Tectonic environment

Simultaneous measurement of aqueous redox-sensitive elements and their species across the soil-water interface

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2021年第4期33卷 1-10页

作者： Zhao-feng yuan Williamson Gustave Raju Sekar Jonathan Bridge Jia-Yue Wang Wei-Jia feng Bin Guo Zheng Chen Department of Health and Environmental Sciences Xi’an Jiaotong-Liverpool UniversityJiangsu 215123China Department of Environmental Science University of LiverpoolLiverpool L697ZXUK Department of Plant Science Tarim UniversityXinjiang 843300China Chemistry Environmental&Life SciencesUniversity of The BahamasNassauBahamas Department of Biological Sciences Xi’an Jiaotong-Liverpool UniversityJiangsu 215123China Department of Natural and Built Environment Sheffield Hallam UniversitySheffield S11WBUK Institute of Environment ResourceSoil and FertilizerZhejiang Academy of Agricultural SciencesZhejiang 310021China

The redox-sensitive elements,such as iron,manganese,sulfur,phosphorus,and arsenic,shift their speciation every millimeter(mm)across the soil-water interface in the flooded soil *** of element speciation at this high-resolution(HR)within the SWI is still *** key challenge lies in obtaining sufficient porewater samples at specific locations along the soil gradient for downstream *** with an optimized inductively coupled plasma mass spectrometry(ICP-MS)method and a HR porewater sampler,we demonstrate mm-scale element profiles mapping across the SWI in paddy *** of iron and manganese(>10 mg/L)were measured by ICP-MS in an extended dynamic range mode to avoid signal *** iron profile along the SWI generated by the ICP-MS method showed no significant difference(p<0.05)compared to that measured independently using a colorimetric ***,four arsenic(arsenite,arsenate,monomethylarsonic and dimethylarsinic acid),two phosphorus(phosphite and phosphate)and two sulfur(sulfide and sulfate)species were separated in 10 min by ion chromatography-ICP-MS with the NH_(4)HCO_(3)mobile *** verified the technique using paddy soils collected from the field,and present the mm-scale profiles of iron,manganese,and arsenic,phosphorus,sulfur species(relative standard deviation<8%).The technique developed in this study will significantly promote the measurement throughput in limited samples(e.g.100μL)collected by HR samplers,which would greatly facilitate redox-sensitive elements biogeochemical cycling in saturated soils.

关键词： Porewater Soil-water interface Arsenic Iron Sulfur Species

Techniques for increasing the yield of stem cell-derived exosomes:what factors may be involved?

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2022年第7期65卷 1325-1341页

作者： Zi-yuan feng Qing-Yi Zhang Jie Tan Hui-Qi Xie Laboratory of Stem Cell and Tissue Engineering Orthopedic Research InstituteMed-X Center for MaterialsState Key Laboratory of BiotherapyWest China HospitalSichuan UniversityChengdu 610041China

Exosomes are nano-scale extracellular vesicles secreted by cells and constitute an important part in the cell-cell *** main contents of the exosomes include proteins,micro RNAs,and *** mechanism and safety of stem cell-derived exosomes have rendered them a promising therapeutic strategy for regenerative ***,limited yield has restrained full explication of their functions and clinical *** address this,various attempts have been made to explore the up-and down-stream manipulations in a bid to increase the production of *** review has recapitulated factors which may influence the yield of stem cell-derived exosomes,including selection and culture of stem cells,isolation and preservation of the exosomes,and development of artificial exosomes.

关键词： exosome stem cell yield therapy

New clues to jet launching: The inner disks in radio loud quasars may be more stable

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2019年第6期62卷 108-121页

作者： ZhenYi Cai YuHan Sun JunXian Wang FeiFan Zhu WeiMin Gu feng yuan CAS Key Laboratory for Research in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China School of Astronomy and Space Science University of Science and Technology of China Department of Astronomy and Astrophysics 537 Davey Lab The Pennsylvania State University Department of Astronomy Xiamen University SHAO-XMU Joint Center for Astrophysics Xiamen University Shanghai Astronomical Observatory Chinese Academy of Sciences

Jet launching in radio loud(RL) quasars is one of the fundamental problems in astrophysics. Exploring the differences in the inner accretion disk properties between RL and radio quiet(RQ) quasars might yield helpful clues to this puzzle. We previously discovered that the shorter term UV/optical variations of quasars are bluer than the longer term ones, i.e., the so-called timescaledependent color variation. This is consistent with the scheme that the faster variations come from the inner and hotter disk regions,thus providing a useful tool to map the accretion disk which is otherwise unresolvable. In this work we compare the UV/optical variations of RL quasars in SDSS Stripe 82 to those of several RQ samples, including those matched in redshift-luminosity-black hole mass and/or color-magnitude. We find that while both RL and RQ populations appear bluer when they brighten, RL quasars potentially show a weaker/flatter dependence on timescale in their color variation. We further find that while both RL and RQ populations on average show similar variation amplitudes at long timescales, fast variations of RL sources appear weaker/smaller(at timescales of ～25-300 d in the observer's frame), and the difference is more prominent in the g-band than in the *** disk simulations can qualitatively reproduce these observed differences if the inner accretion disk of RL quasars fluctuates less based on simple toy models. Though the implications are likely model dependent, the discovery points to an interesting diagram that magnetic fields in RL quasars may be prospectively stronger and play a key role in both jet launching and the stabilization of the inner accretion disk.

关键词： accretion and accretion disks quasars galactic jets

Responsive Polymeric Nanoparticles for Biofilm-infection Control

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2021年第11期39卷 1376-1391页

作者： Lin-Zhu Su Yong Liu yuan-feng Li Ying-Li An Lin-Qi Shi State Key Laboratory of Medicinal Chemical Biology Key Laboratory of Functional Polymer MaterialsMinistry of EducationInstitute of Polymer ChemistryCollege of ChemistryNankai UniversityTianjin 300071China Engineering Research Center of Clinical Functional Materials and Diagnosis&Treatment Devices of Zhejiang Province Wenzhou InstituteUniversity of Chinese Academy of SciencesOujiang LaboratoryWenzhou 325000China

With the emergence of multidrug resistance(MDR)in many pathogens,bacterial infections are becoming a growing threat to public *** frightening scenario is due largely to the formation of biofilms,in which the bacteria are extremely recalcitrant to the conventional antibiotic *** address the emergence of MDR and biofilm-associated infections,numerous polymer-based materials have been designed and prepared *** subject of this perspective is the recent development of polymer-based materials that have been applied to combat multidrug-resistant pathogens,to prevent the formation of biofilms,or enhance the eradication efficacy to mature biofilms via killing biofilm-bacteria or dispersing *** advantages and shortcomings of these polymer-based materials are discussed,as well as the challenges we are facing in the clinical translation of these systems.

关键词： Antibacterial Biofilm Multidrug resistance Polymeric nanoparticles Stimuli-responsive

Positon and hybrid solutions for the(2+1)-dimensional complex modified Korteweg-de Vries equations

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2023年第4期32卷 118-124页

作者：袁丰 Behzad Ghanbari College of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China Department of Basic Science Kermanshah University of TechnologyKermanshahIran

Solving nonlinear partial differential equations have attracted intensive attention in the past few decades. In this paper, the Darboux transformation method is used to derive several positon and hybrid solutions for the(2+1)-dimensional complex modified Korteweg–de Vries equations. Based on the zero seed solution, the positon solution and the hybrid solutions of positon and soliton are constructed. The composition of positons is studied, showing that multi-positons of(2+1)-dimensional equations are decomposed into multi-solitons as well as the(1+1)-dimensions. Moreover, the interactions between positon and soliton are analyzed. In addition, the hybrid solutions of b-positon and breather are obtained using the plane wave seed solution, and their evolutions with time are discussed.

关键词： positon solution b-positon solution breather solution the hybrid solution the Darboux transformation

Evolution of Er^(3+) Distribution in the Oxyfluoride Glass Ceramics with Heating

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2007年第3期26卷 303-308页

作者： MA En CHEN Da-Qin HU Zhong-Jian LIU feng HUANG Zi-Xiang BAO feng WANG yuan-Sheng State Key Laboratory of Structural Chemistry Fujian Institute of Research on theStructure of Matter Chinese Academy of Sciences Fuzhou Fujian 350002 China

The distribution characteristics of Er^3＋ ions doped in the oxyfluoride glass ceramics containing LaF3 nanocrystals heat-treated at 650 ℃ for different durations were investigated. The results of the integral absorption cross-section analysis demonstrated that the partition fraction of Er^3＋ in LaF3 nanocrystals increases with prolonging of heating time, The anomalous phenomena of Er^3＋ emissions in the up-and the down-conversion fluorescence spectra are well explained based on the calculated results.

关键词： oxyfluoride glass ceramics rare earth nanocrystal up-conversion integral absorption cross-section

Sensitive determination of inosine RNA modification in single cell by chemical derivatization coupled with mass spectrometry analysis

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第10期34卷 98-101页

作者： Wan-Bing Tao Neng-Bin Xie Qing-Yun Cheng Yu-Qi feng Bi-feng yuan College of Chemistry and Molecular Sciences Department of Radiation and Medical OncologyZhongnan Hospital of Wuhan UniversityWuhan UniversityWuhan 430071China School of Public Health Wuhan UniversityWuhan 430071China Research Center of Public Health Renmin Hospital of Wuhan UniversityWuhan 430060China Cancer Precision Diagnosis and Treatment and Translational Medicine Hubei Engineering Research Center Zhongnan Hospital of Wuhan UniversityWuhan Research Center for Infectious Diseases and CancerChinese Academy of Medical SciencesWuhan 430071China

Inosine is a vital RNA modification across three kingdoms of *** has been demonstrated that inosine plays important roles in modulation of the fate of *** the current study,we developed a highly sensitive method to determine inosine in a single cell by N-cyclohexyl-N’-β-(4-methylmorpholinium)ethylcarbodiimide p-toluenesulfonate(CMCT)derivatization in combination with mass spectrometry *** results showed that the detection sensitivity of inosine was increased by 556-fold after CMCT derivatization,with the limit of detection(LOD)being 4.5 *** the established method,we could detect inosine from 13.0 pg of total RNA of HEK293T ***,inosine in RNA from a single cell could also be clearly detected due to the improved detection ***,we found the level of inosine in RNA of sleep-deprived mice was significantly increased compared to the control mice,indicating that inosine is associated with sleep behavior and might be a potential indicator of sleep *** together,the chemical derivatization coupled with mass spectrometry analysis offers a valuable tool in determination of endogenous RNA modifications in a single cell,which should benefit the functional study of RNA modification in rare clinical samples.

关键词： Inosine RNA modification CMCT Derivatization Mass spectrometry Single cell

Utilization of an H-reversal trajectory of a solar sail for asteroid deflection

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2011年第10期11卷 1123-1133页

作者： Sheng-Ping Gong Jun-feng Li Xiang-yuan Zeng School of Aerospace Tsinghua University Beijing 100084 China

Near Earth Asteroids have a possibility of impacting the Earth and always represent a threat. This paper proposes a way of changing the orbit of the asteroid to avoid an impact. A solar sail evolving in an H-reversal trajectory is utilized for asteroid deflection. Firstly, the dynamics of the solar sail and the characteristics of the H-reversal trajectory are analyzed. Then, the attitude of the solar sail is optimized to guide the sail to impact the target asteroid along an H-reversal trajectory. The impact velocity depends on two important parameters： the minimum solar distance along the trajectory and lightness number of the solar sail. A larger lightness number and a smaller solar distance lead to a higher impact velocity. Finally, the deflection capability of a solar sail impacting the asteroid along the H-reversal trajectory is discussed. The results show that a 10kg solar sail with a lead-time of one year can move Apophis out of a 600-m keyhole area in 2029 to eliminate the possibility of its resonant return in 2036.

关键词： asteroid -- techniques: miscellaneous -- solar sail