检索结果-南通市图书馆

The ALMaQUEST Survey ⅩⅤ:The dependence of the molecular-to-atomic gas ratios on resolved optical diagnostics

Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 174-196页

作者： Niankun Yu Zheng Zheng Chao-Wei Tsai Pei Zuo Sara L.Ellison david v.stark Di Li Jingwen Wu Karen L.Masters Ting Xiao Yinghui Zheng Zongnan Li Kai Zhang Hongying Chen Shu Liu Sihan Jiao Fanyi Meng National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Key Laboratory of Radio Astronomy and Technology Chinese Academy of SciencesBeijing 100101China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Department of Physics&Astronomy University of VictoriaVictoriaV8P 1A1Canada Departments of Physics and Astronomy Haverford CollegeHaverford19041USA Space Telescope Science Institute San Martin Dr.Baltimore 21218USA Zhejiang Laboratory Hangzhou 311121China New Cornerstone Science Laboratory Shenzhen 518054China School of Physics Zhejiang UniversityHangzhou 310058China

The atomic-to-molecular gas conversion is a critical step in the baryon cycle of galaxies,which sets the initial conditions for subsequent star formation and influences the multi-phase interstellar *** compiled a sample of 94 nearby galaxies with observations of multi-phase gas contents by utilizing public H_(Ⅰ),CO,and optical IFU data from the Ma NGA survey together with new FAST H_(Ⅰ)*** agreement with previous results,our sample shows that the global molecular-to-atomic gas ratio(R_(mol)≡log M_(H2)/M_(H_(Ⅰ)))is correlated with the global stellar mass surface densityμ_*with a Kendall'sτcoefficient of 0.25 and pv-r color,and not related to the specific star formation rate(sSFR).The cold gas distribution and kinematics inferred from the H_(Ⅰ)and CO global profile asymmetry and shape do not significantly rely on R_(mol).Thanks to the availability of kpc-scale observations of MaNGA,we decompose galaxies into H_(Ⅱ),composite,and AGN-dominated regions by using the BPT *** increasing R_(mol),the fraction of H_(Ⅱ)regions within 1.5 effective radius decreases slightly;the density distribution in the spatially resolved BPT diagram also changes significantly,suggesting changes in metallicity and ionization *** with high R_(mol)tend to have high oxygen abundance,both at one effective radius with a Kendall'sτcoefficient of 0.37(pvestigated here,the oxygen abundance at one effective radius has the strongest relation with global R_(mol).The dependence of gas conversion on gas distribution and galaxy ionization states is *** contrast,the observed positive relation between oxygen abundance(μ_(*))and R_(mol)indicates that the gas conversion is efficient in regions of high metallicity(density).

关键词： Galaxies baryon cycle radio lines H_(Ⅰ)21 cm atomic-to-molecular gas conversion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Blast waveform tailoring using controlled venting in blast simulators and shock tubes

引用

Defence Technology（防务技术） 2024年第7期37卷 14-26页

作者： Edward Chern Jinn Gan Alex Remennikov david Ritzel Faculty of Engineering and Information Sciences University of WollongongWollongongNSW2522Australia Dyn-FX Consulting Ltd 19 Laird Ave NorthAmherstburgONN9V 2T5Canada

A critical challenge of any blast simulation facility is in producing the widest possible pressure-impulse range for matching against equivalent high-explosive *** tubes and blast simulators are often constrained with the lack of effective ways to control blast wave profiles and as a result have a limited performance *** wave shaping techniques employed in some facilities are reviewed but often necessitate extensive geometric modifications,inadvertently cause flow anomalies,and/or are only applicable under very specific *** paper investigates controlled venting as an expedient way for waveforms to be tuned without requiring extensive modifications to the driver or existing geometry and could be widely applied by existing and future blast simulation and shock tube *** use of controlled venting is demonstrated experimentally using the Advanced Blast Simulator(shock tube)at the Australian National Facility of Physical Blast Simulation and via numerical flow simulations with Computational Fluid *** venting is determined as an effective method for mitigating the impact of re-reflected waves within the blast *** control method also allows for the adjustment of parameters such as tuning the peak overpressure,the positive phase duration,and modifying the magnitude of the negative phase and the secondary shock of the blast *** paper is concluded with an illustration of the potential expanded performance range of the Australian blast simulation facility when controlled venting for blast waveform tailoring as presented in this paper is applied.

关键词： Advanced blast simulator Shock wave propagation Far-field explosion Blast loads Blast waves Computational fluid dynamics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Utilization of pH-driven methods to fortify nanoemulsions with multiple polyphenols

引用

Food Science and Human Wellness 2024年第4期13卷 1943-1950页

作者： Hualu Zhou Bingjing Zheng david Julian McClements Department of Food Science and Technology College of Agricultural and Environmental SciencesUniversity of GeorgiaGriffinGA 30223USA Biopolymers and Colloids Laboratory Department of Food ScienceUniversity of MassachusettsAmherstMA 01003USA Department of Food Science&Bioengineering Zhejiang Gongshang UniversityHangzhou 310018China

Simple but effective methods are required to incorporate multiple bioactive polyphenols into delivery systems to increase their dispersibility,stability and *** developed and tested three p Hdriven protocols for creating nanoemulsions loaded with multiple lipophilic *** protocols differed in how the different polyphenols were incorporated into the *** impact of these three methods on the formation,properties,and gastrointestinal fate of nanoemulsions loaded with curcumin,resveratrol,and quercetin was *** three methods produced nanoemulsions with similar initial particle properties:droplet diameters(0.15,0.16,and 0.15μm)and zeta-potentials(–59,–58,and–58 m v),***,the average encapsulation efficiencies(82%,88%,and 61%),gastrointestinal stabilities(83%,97%,and 29%)and bioaccessibilities(77%,90%,and 73%)for curcumin,resveratrol,and quercetin were somewhat *** particular,more quercetin degradation occurred using the approach that held it under alkaline conditions for extended *** general,the p H-driven method provides researchers with a versatile approach of incorporating multiple polyphenols with different characteristics into functional food and beverages using a simple and inexpensive method.

关键词： Polyphenols pH-Driven encapsulation Nanoemulsions Gastrointestinal fate Functional foods

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Construction of a broad-host-range Anderson promoter series and particulate methane monooxygenase promoter variants expand the methanotroph genetic toolbox

引用

Synthetic and Systems Biotechnology 2024年第2期9卷 250-258页

作者： Etash H.Bhat Jessica M.Henard Spencer A.Lee Dustin McHalffey Mahith S.Ravulapati Elle v.Rogers Logan Yu david Skiles Calvin A.Henard Department of Biological Sciences and BioDiscovery Institute University of North TexasDentonTXUSA

Methanotrophic bacteria are currently used industrially for the bioconversion of methane-rich natural gas and anaerobic digestion-derived biogas to valuable *** bacteria may also serve to mitigate the negative effects of climate change by capturing atmospheric greenhouse *** genetic tools have previously been developed for genetic and metabolic engineering of ***,the available tools for use in methanotrophs are significantly underdeveloped compared to many other industrially relevant bacteria,which hinders genetic and metabolic engineering of these *** such,expansion of the methanotroph genetic toolbox is needed to further our understanding of methanotrophy and develop biotechnologies that leverage these unique microbes for mitigation and conversion of methane to valuable ***,we determined the copy number of three broad-host-range plasmids in Methylococcus capsulatus Bath and Methylosinus trichosporium OB3b,representing phylogenetically diverse Gammaproteobacterial and Alphaproteobacterial methanotrophs,***,we show that the commonly used synthetic Anderson series promoters are functional and exhibit similar relative activity in *** and *** OB3b,but the synthetic series had limited ***,we mutagenized the native *** particulate methane monooxygenase promoter and identified variants with activity that expand the activity range of synthetic,constitutive promoters functional not only in ***,but also in Escherichia ***,the tools developed here advance the methanotroph genetic engineering toolbox and represent additional synthetic genetic parts that may have broad applicability in Pseudomonadota bacteria.

关键词： Methanotroph Methane monooxygenase Promoter Metabolic engineering Synthetic biology

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The great catastrophe: causes of the Permo-Triassic marine mass extinction

引用

National Science Review 2024年第1期11卷 37-50页

作者： Paul B.Wignall david P.G.Bond School of Earth & Environment University of Leeds School of Environmental Sciences University of Hull

The marine losses during the Permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). Planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the crisis to a ～55 kyr interval straddling the Permo-Triassic boundary. Many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the Permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(verwhelming evidence for rapid warming during the crisis makes this an unlikely cause. Finally, whilst the extinction is well studied in equatorial latitudes, a different history is found in northern Boreal latitudes

关键词： ocean anoxia ocean acidification siltation productivity collapse volcanic winter

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Old-growth mixed dipterocarp forests show variable losses and gains in aboveground biomass and standing carbon over forty years

引用

Forest Ecosystems 2024年第1期11卷 14-23页

作者： Sisira Ediriweera Champika Bandara Tithira Lakkana Shanika Jayasinghe david Woodbury Arun Dayanandan B.M.P.Singhakumara Xiangcheng Mi I.A.U.N.Gunatilleke C.v.S.Gunatilleke Mark SAshton Department of Science and Technology Uva Wellassa UniversityBadullaSri Lanka The Forest School Yale School of the EnvironmentYale UniversityNew HavenCT06511USA Department of Forestry and Environmental Science University of Sri JayewardenepuraNugegodaSri Lanka State Key Laboratory of vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing100093China Botany Department University of PeradeniyaPeradeniyaSri Lanka

Background:No studies have documented long-term trends in aboveground biomass(AGB)for mixed-dipterocarp forests(MDF),the dominant rain forest type in tropical wet equatorial *** our study,we sought to document such trends over forty years across three sites representing lowland to lower montane ***:To do this,we established fifty 100 m×25 m plots in 1978 across three sites sampled along an elevation gradient,identified as mature old-growth *** measured trees for diameter at breast height that we identified to species and *** took wood samples to calculate species wood-specific *** re-measured plots in 1998 and again in ***:We show standing AGB for all sites combined to be 517.52 Mg·ha^(-1)in 1978,but this declined by 17%over 40 years to 430.11 Mg·ha^(-1).No differences exist among sites in AGB primarily because of considerable within site variation;but interactions of time with site show declines across sites were not uniform,one remained about the *** few species represented a high proportion of the AGB with the top five species comprising between 34%and 65%,depending upon site and year *** species,Mesua nagassarium,represented a disproportionately large amount of AGB and decline over time,particularly at the low elevation ***:Our results are directly relevant to estimating AGB and standing carbon sequestered in *** study is the first to demonstrate varying but overall,declining trends in amounts of AGB among forests making predictions of biomass and standing carbon in MDF difficult over wide regions.

关键词： Western ghats Shorea spp. Southeast Asia Sri Lanka Tropical rain forest Wood specific gravity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

There is more to the knee joint than just the quadriceps:A systematic review with meta-analysis and evidence gap map of hamstring strength,flexibility,and morphology in individuals with gradual-onset knee disorders

引用

Journal of Sport and Health Science 2024年第4期13卷 521-536页

作者： Helder S.Lopes Marina C.Waiteman Liliam B.Priore Neal R.Glaviano david M.Bazett-Jones Ronaldo v.Briani Fabio M.Azevedo School of Science and Technology Physical Therapy DepartmentSao Paulo State University(UNESP)Presidente Prudente 19060-900Brazil Department of Kinesiology College of AgricultureHealth and Natural ResourcesUniversity of ConnecticutStorrsCT 06269USA School of Exercise and Rehabilitation Sciences College of Health and Human ServicesUniversity of ToledoToledoOH 43606USA

Background:Impairments in hamstring strength,flexibility,and morphology have been associated with altered knee biomechanics,pain,and *** the presence of these impairments in individuals with gradual-onset knee disorders is important and may indicate targets for assessment and *** systematic review aimed to synthesize the literature to determine the presence of impairments in hamstring strength,flexibility,and morphology in individuals with gradual-onset knee ***:Five databases(MEDLINE,Embase,CINAHL,SPORTDiscus,and Web of Science)were searched from inception to September *** studies comparing hamstring outcomes(e.g.,strength,flexibility,and/or morphology)between individuals with gradual-onset knee disorders and their unaffected limbs or pain-free controls were ***-analyses for each knee disorder were ***-level certainty was assessed using the Grading of Recommendations Assessment,Development,and Evaluation,and evidence gap maps were ***:Seventy-nine studies across 4 different gradual-onset knee disorders(i.e.,knee osteoarthritis(OA),patellofemoral pain(PFP),chondromalacia patellae,and patellar tendinopathy)were *** with knee OA presented with reduced hamstring strength compared to pain-free controls during isometric(standard mean difference(SMD)=-0.76,95%confidence interval(95%CI):-1.32 to-0.21)and concentric contractions(SMD=-0.97,95%CI:-1.49 to-0.45).Individuals with PFP presented with reduced hamstring strength compared to painfree controls during isometric(SMD=-0.48,95%CI:-0.82 to-0.14),concentric(SMD=-1.07,95%CI:-2.08 to-0.06),and eccentric contractions(SMD=-0.59,95%CI:-0.97 to-0.21).No differences were observed in individuals with patellar *** with PFP presented with reduced hamstring flexibility when compared to pain-free controls(SMD=-0.76,95%CI:-1.15 to-0.36).Evidence gap maps identified insufficient evidence for chondromalacia patel

关键词： Chondromalacia patellae Knee flexors Knee osteoarthritis Patellar tendinopathy Patellofemoral pain

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Core needle biopsy for thyroid nodules assessment-a new horizon?

引用

World Journal of Clinical Oncology 2024年第5期15卷 580-586页

作者： david D Dolidze Serghei Covantsev Grigorii M Chechenin Natalia v Pichugina Anastasia v Bedina Anna Bumbu Department of Clinical Research and Development Botkin HospitalMoscow 125284Russia Department of Surgery Russian Medical Academy of Continuous Professional EducationMoscow 125445Russia Emergency Surgery No.76 Botkin HospitalMoscow 125284Russia Department of Surgery Botkin HospitalMoscow 125284Russia Department of Medical Ultrasonography Botkin HospitalMoscow 125284Russia Medicine Moscow State Medical University I.M.SechenovMoscow 119048Russia Department of Oncology Botkin HospitalMoscow 125284Russia

Ultrasound-guided fine-needle aspiration is the standard for evaluating thyroid nodules with a high safety profile and a relatively low number of non-diagnostic cytological ***,this diagnostic method traditionally has its weak *** diagnostic categories such as BethesdaⅠ,ⅢandⅣare not reliable for thyroid carcinoma risk *** advancements in a core needle biopsy made it possible to use this tool as a new method for thyroid nodules *** main feature of this method is the use of thin needles(18-21G)and guns with an automatic trigger *** histological material collected with the use of a core needle biopsy is usually superior to ***,the core needle biopsy can be used as a complementary technique to a standard fine needle aspiration in difficult and dubious cases of thyroid neoplasia with uncertain malignant potential.

关键词： Core-needle biopsy Thyroid Follicular tumor Fine-needle aspiration Thyroid cancer

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computational study of flow separation in truncated ideal contour nozzles under high-altitude conditions

International Journal of Fluid Engineering

引用

International Journal of Fluid Engineering 2024年第1期 21-30页

作者： Ijas Muhammed v v Shamsia Banu N Abhilash Suryan vincent Lijo david Simurda Heuy Dong Kim College of Engineering Trivandrum Government Engineering College Thrissur Faculty of Mechanical Engineering Technical University of Liberec Andong National University

Flow separation in rocket nozzles has been studied mostly under sea-level conditions, which fail to take into account changes in ambient density and ambient pressure during the flight of a rocket. In the present study, numerical analysis is conducted of flow characteristics within a truncated ideal contour(TIC) nozzle to investigate the influence of ambient density and pressure on flow separation. Six different altitudes from a typical flight are considered, from a very low altitude to a high altitude. The flow is analyzed by varying the nozzle pressure ratios corresponding to these altitudes. Both cold flow and hot flow simulations are conducted. The locations of separation positions at various altitude conditions are accurately captured and are found to be in good agreement with experimental results. The results of the study establish that for a given nozzle pressure ratio, the flow separation point is shifted upstream with increasing altitude. This clearly points to a dependence of separation position on the altitude of operation for TIC rocket nozzles.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Quantification of perfluorinated compounds in atmospheric particulate shows potential connection with environmental event

引用

Journal of Environmental Sciences 2024年第2期136卷 237-247页

作者： Hua Tang Ying Wang Shengling Si Hongli Li david Da Yong Chen National Institute of Metrology 18 BeisanhuandongluChaoyang DistrictBeijing 100029China School of Chemistry and Materials Science Nanjing Normal UniversityNanjing 210023China Si Chuan Zhong Ce Biao Wu Technology Co.Ltd. Sichuan 610052China Department of Chemistry University of British ColumbiaVancouver V6T 1Z1BCCanada

A method of quantification of perfluorinated compounds(PFCs)from atmospheric particulate matter(APM)is described.A single step pretreatment method,selective pressurized liquid extraction(SPLE),was developed to reduce the high matrix background and avoid contamination from commonly used multiple sample pretreatment *** effective sorbent was selected to purify the PFCs during SPLE,followed by liquid chromatography-tandem mass spectrometry(LC–MS/MS),for quantification of *** affecting the SPLE efficiency,including temperature,static extraction time,and number of extraction cycles used,were *** optimum conditions were found to be 120℃,10 min,and 3 cycles,***-MS/MS method was developed to obtain the optimal sensitivity specific to *** method detection limits(MDLs)were 0.006 to 0.48 ng/g for the PFCs studied and the linear response range was from 0.1 to 100 ng/*** ensure accurate values were obtained,each step of the experiment was evaluated and controlled to prevent *** optimized method was tested by performing spiking experiments in natural particulate matter matrices and good rates of recovery and reproducibility were obtained for all target ***,the method was successfully used to measure 16 PFCs in the APM samples collected in Beijing over five years from 2015 to *** is observed that some PFCs follow the trend of total PFC changes,and can be attributed to the environment influencing events and policy enforcement,while others don't seem to change as much with time of the year or from year to year.

关键词： Selective pressurized liquid extraction Liquid chromatography-mass spectrometry Perfluorinated compounds Atmospheric particulate matter Pollution control

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：