A log-based method for fine-scale evaluation of lithofacies and its applications to the Gulong shale in the Songliao Basin,Northeast China

The Gulong shale demonstrates high clay content and pronounced thin laminations,with limited vertical variability in log curves,complicating lithofacies classification.To comprehend the distribution and compositional features of lithofacies in the Gulong shale for optimal sweet spot selection and reservoir stimulation,this study introduced a lithofacies classification scheme and a log-based lithofacies evaluation method.Specifically,theΔlgR method was utilized for accurately determining the total organic carbon(TOC)content;a multi-mineral model based on element-to-mineral content conversion coefficients was developed to enhance mineral composition prediction accuracy,and the microresistivity curve variations derived from formation micro-image(FMI)log were used to compute lamination density,offering insights into sedimentary structures.Using this method,integrating TOC content,sedimentary structures,and mineral compositions,the Qingshankou Formation is classified into four lithofacies and 12 sublithofacies,displaying 90.6%accuracy compared to core description outcomes.The classification results reveal that the northern portion of the study area exhibits more prevalent fissile felsic shales,siltstone interlayers,shell limestones,and dolomites.Vertically,the upper section primarily exhibits organic-rich felsic shale and siltstone interlayers,the middle part is characterized by moderate organic quartz-feldspathic shale and siltstone/carbonate interlayers,and the lower section predominantly features organic-rich fissile felsic/clayey felsic shales.Analyzing various sublithofacies in relation to seven petrophysical parameters,oil test production,and fracturing operation conditions indicates that the organic-rich felsic shales in the upper section and the organic-rich/clayey felsic shales in the lower section possess superior physical properties and oil content,contributing to smoother fracturing operation and enhanced production,thus emerging as dominant sublithofacies.Conversely,thin interlayers such as siltstones and limestones,while producing oil,demonstrate higher brittleness and pose great fracturing operation challenges.The methodology and insights in this study will provide a valuable guide for sweet spot identification and horizontal well-based exploitation of the Gulong shale.

A new method for quantitative evaluation of shale laminae using electrical image logging

Shale oil reservoirs are generally characterized by complex mineral compositions, rapid lithofacies changes, and thin laminae. Explorations have confirmed that the type and density of shale laminae significantly influence reservoir quality, highlighting the importance of accurately identifying these laminae through well logging for effective shale reservoir evaluation. Presently, relevant technologies primarily focus on the qualitative identification of shale laminae using vertical slab images from image logs. However, influenced by the complex borehole conditions and image logging quality, this approach is less effective in identifying millimeter-scale laminae. This study proposes a new method for achieving high-resolution slab images and quantitatively evaluating the laminae using electrical image logs. The new method effectively improves the processing accuracy of slab images by delicately flattening and aligning the button electrode curves derived from electrical image logs point by point. Meanwhile, it allows for the accurate quantitative evaluation of the lamina number through precise identification of peaks and troughs in microelectrode curves. As demonstrated by the applications in shale oil reservoirs in the Gulong area in Daqing and the Ganchagou area in Qinghai, the proposed method can significantly improve accuracy compared to traditional slab images. Furthermore, the lamination index calculated using this method is highly consistent with the lamina number observed in cores. This study provides a new technical method for the quantitative lamina evaluation and rock structure analysis of shale reservoirs.

COVID-19大流行期间流感活动呈“断崖式”下降——佩戴口罩、人员流动变化及SARS-CoV-2干扰的作用

一般情况下,每年冬季是季节性流感高发季节,但在当前2019冠状病毒病(COVID-19)大流行期间,全球季节性流感活动呈“断崖式”下降。为应对即将到来的流感季节,亟需弄清这种前所未有的流感低水平流行的原因。本文中,我们探索了一种国家特异性推理模型,利用该模型估计中国、英国和美国这三个国家中佩戴口罩、人员流动变化(国际和国内)以及严重急性呼吸综合征冠状病毒2型(SARS-CoV-2)干扰的影响。结果发现,在这些地区增加一周佩戴口罩的干预措施,流感活动可减少11.3%~35.2%。实施一周的限制人员流动措施对国际(1.7%~6.5%)和国内社区(1.6%~2.8%)的影响较小。2020年至2021年,仅佩戴口罩这一项干预措施就可使阳性率下降13.3%至19.8%。仅人员流动变化可使阳性率降低5.2%至14.0%,其中79.8%~98.2%归因于国际旅行限制。SARS-CoV-2干扰仅在2019年至2020年具有统计学显著效应。中国北方地区及英国的阳性百分比分别降低7.6%(2.4~14.4)和10.2%(7.2~13.6)。探索所得出的结果对了解非药物干预措施和其他呼吸系统疾病背景下的流感演变有一定意义,有助于制定卫生政策,并可为公共卫生措施的个性化设计提供信息。

Effect of Preparation Method on Catalytic Properties of Double Perovskite Oxides LaSrFeMo_0.9Co_0.1O₆for Methane Combustion

The double perovskite oxides LaSrFeMo0.9Co0.1O6 was prepared by co-precipitation method and sol-gel method. The title catalysts were calcined at 800°C and characterized by XRD H2-TPR, SEM and TG-DTA techniques. The catalytic activity was evaluated for methane combustion. The specific surface area of them was calculated by BET model. The samples exhibit significant catalytic activity for methane combustion at 800°C. Upon calcination at 800°C, the LaSrFeMo0.9Co0.1O6 prepared by sol-gel method retains a specific surface area of 24 m2.g-1 and shows an excellent activity for methane combustion (the conversion of 10% and 90% are obtained at 505°C and 660°C, respectively).

(FeO)_(2)FeBO_(3) nanoparticles attached on interconnected nitrogen-doped carbon nanosheets serving as sulfur hosts for lithium-sulfur batteries

There are still many challenges including low conductivity of cathodes,shuttle effect of polysulfides,and significant volume change of sulfur during cycling to be solved before practical applications of lithium-sulfur(Li-S)batteries.In this work,(FeO)_(2)FeBO_(3) nanoparticles(NPs)anchored on interconnected nitrogen-doped carbon nanosheets(NcNs)were synthesized,serving as sulfur carriers for Li-S batteries to solve such issues.NcNs have the cross-linked network structure,which possess good electrical conductivity,large specific surface area,and abundant micropores and mesopores,enabling the cathode to be well infiltrated and permeated by the electrolyte,ensuring the rapid electron/ion transfer,and alleviating the volume expansion during the electrochemical reaction.In addition,polar(FeO)_(2)FeBO_(3) can enhance the adsorption of polysulfides,effectively alleviating the polysulfide shuttle effect.Under a current density of 1.0 A·g^(-1),the initial discharging and charging specific capacities of the(FeO)_(2)FeBO_(3)@NCNs-2/S electrode were obtained to be 1113.2 and 1098.3mA·h·g^(-1),respectively.After 1000 cycles,its capacity maintained at 436.8 mA·h·g^(-1),displaying a decay rate of 0.08%per cycle.Therefore,combining NCNs with(FeO)_(2)FeBO_(3) NPs is conducive to the performance improvement of Li-S batteries.

Nitrogen-doped carbon-coated hollow SnS_(2)/NiS microflowers for high-performance lithium storage

Nitrogen-doped carbon-coated hollow SnS_(2)/NiS(SnS_(2)/NiS@N–C)microflowers were obtained using NiSn(OH)6 nanospheres as the template via a solventthermal method followed by the polydopamine coating and carbonization process.When served as an anode material for lithium-ion batteries,such hollow SnS_(2)/NiS@N–C microflowers exhibited a capacity of 403.5 mAh·g^(−1) at 2.0 A·g^(−1) over 200 cycles and good rate performance.The electrochemical reaction kinetics of this anode was analyzed,and the morphologies and structures of anode materials after the cycling test were characterized.The high stability and good rate performance were mainly due to bimetallic synergy,hollow micro/nanostructure,and nitrogen-doped carbon layers.The revealed excellent electrochemical energy storage properties of hollow SnS_(2)/NiS@N–C microflowers in this study highlight their potential as the anode material.

Attitudes Regarding Influenza Vaccination Among Public Health Workers during COVID-19 Pandemic — China, September 2022

Summary What is already known about this topic?Public health workers(PHWs)were listed as a priority group recommended for influenza vaccination during the coronavirus disease 2019(COVID-19)pandemic.Understanding the drivers of influenza vaccine hesitancy among PHWs can promote influenza vaccination in the COVID-19 pandemic.

SnO_(2)nanotubes with N-doped carbon coating for advanced Li-ion battery anodes

Tin dioxide nanotubes with N-doped carbon layer(SnO_(2)/N-C NTs)were synthesized through a MoO3 nanorod-based sacrificial template method,dopamine polymerization and calcination process.Applied to the Li-ion battery,SnO_(2)/N-C NTs exhibited excellent electrochemical properties,with a first discharge capacity of 1722.3 mAh·g^(−1)at 0.1 A·g^(−1)and a high capacity of 1369.3 mAh·g^(−1)over 100 cycles.The superior electrochemical performance is ascribed to the N-doped carbon layer and tubular structure,which effectively improves the electrical conductivity of the composites,accelerates the migration of Li+and electrons,and alleviates the volume change of the anode to a certain extent.

季节性流感疫苗和新型冠状病毒疫苗同时接种工作的思考和建议

在新型冠状病毒肺炎(新冠肺炎)全球大流行的环境下, 流感的流行强度、流行特征和人群的感染风险均呈现出新的特点, 且全球多地区已出现新冠肺炎和流感共同流行的情况。新冠肺炎和流感的传播方式、临床症状等方面相似, 流感病毒与新型冠状病毒对细胞的作用机制上也存在相似之处, 同时做好新冠肺炎和流感的防控工作具有较强可行性和重大现实意义。本文从流感疫苗接种预防共同感染、流感疫苗和新冠病毒疫苗同时接种等方面, 探讨了流感和新冠共同防控的相关策略和措施, 提出了相应的思考和建议, 以期为季节性流感疫苗和新型冠状病毒疫苗接种策略的制订提供科学支撑。

The Incoming Influenza Season—China,the United Kingdom,and the United States,2021–2022

Introduction:Seasonal influenza activity has declined globally since the widespread of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)transmission.There has been scarce information to understand the future dynamics of influenza—and under different hypothesis on relaxation of nonpharmaceutical interventions(NPIs)in particular—after the disruptions to seasonal patterns.Methods:We collected data from public sources in China,the United Kingdom,and the United States,and forecasted the influenza dynamics in the incoming 2021–2022 season under different NPIs.We considered Northern China and Southern China separately,due to the sharp difference in the patterns of seasonal influenza.For the United Kingdom,data were collected for England only.Results:Compared to the epidemics in 2017–2019,longer and blunter influenza outbreaks could occur should NPIs be fully lifted,with percent positivity varying from 10.5 to 18.6 in the studying regions.The rebounds would be smaller if the maskwearing intervention continued or the international mobility stayed low,but sharper if the mask-wearing intervention was lifted in the middle of influenza season.Further,influenza activity could stay low under a much less stringent mask-wearing intervention coordinated with influenza vaccination.Conclusions:The results added to our understandings of future influenza dynamics after the global decline during the coronavirus disease 2019(COVID-19)pandemic.In light of the uncertainty on the incoming circulation strains and the relatively low negative impacts of mask wearing on society,our findings suggested that wearing mask could be considered as an accompanying mitigation measure in influenza prevention and control,especially for seasons after long periods of low-exposure to influenza viruses.Seasonal influenza activity declines globally during the coronavirus disease 2019(COVID-19)pandemic(1–4).For instance,in China,influenza activity,as measured by percentage of submitted specimens testing positive,dropped from 11.8%to 2.0%in 2020–2021 influenza season,compared to the past 5 years(5).The long-period of low-exposure to influenza viruses adds great uncertainty on preparedness for the incoming 2021–2022 influenza season.Influenza vaccination is one of the most effective measures in seasonal influenza prevention and control,but with only a few influenza viruses circulating,it could be difficult to determine the targeted strains for vaccination.In this context,it is of primary importance to identify alternative mitigation measures for the incoming 2021–2022 influenza season,the first season after long periods of virtually no influenza outbreaks worldwide.Using data from China,the United Kingdom,and the United States,we forecasted the influenza activity in the incoming 2021–2022 influenza season under hypothetical scenarios without non-pharmaceutical interventions(NPIs)and with different assumptions on mask-wearing and mobility levels.