Quantitative and Comprehensive Prediction of Shale Oil Sweet Spots in Qingshankou Formation, Songliao Basin

The mud shale of Qingshankou Formation in Songliao Basin is the main rock source and contains rich shale oil resources. The successful development of shale oil depends on evaluating and optimizing the “sweet spots”. To accurately identify and optimize the favorable sweet spots of shale oil in Qingshankou Formation, Songliao Basin, the original logging data were preprocessed in this paper. Then the thin mud shale interlayer of Qingshankou Formation was identified effectively by using the processed logging data. Based on the artificial neural network method, the mineral content of mud shale in Qingshankou Formation was predicted. The lithofacies were identified according to the mineral and TOC content. Finally, a three-dimensional (3-D) model of total organic carbon (TOC), vitrinite reflectance (Ro), mineral content, and rock of Qingshankou Formation in Songliao Basin was established to evaluate and predict the favorable sweet spots of shale oil in the study area. The results show that there are a lot of calcareous and siliceous thin interlayers in Qingshankou Formation, and TOC content is generally between 2% and 3%. Ro is the highest in Gulong sag, followed by Sanzhao sag. The lithofacies mainly consists of felsic shale and mixed shale, mainly in the first member of Qingshankou Formation. Comprehensive analysis shows that shale oil development potential is enormous in the eastern part of Sanzhao Sag and the northern part of Gulong Sag.

电催化CO_(2)还原过程中非均相界面的动态行为

自工业革命以来,CO_(2)的过量排放导致了环境污染和气候变化,对人类可持续发展造成了极大的威胁.由可再生电力驱动的电催化CO_(2)还原反应(CO_(2)RR)技术可在较温和的条件下将CO_(2)转化为高附加价值的燃料和化学品,因而是一种有效的CO_(2)转换和利用的方法.尽管电催化CO_(2)RR已经取得了较大的研究进展,但其工业化应用依旧面临着许多挑战:CO_(2)RR的反应路径涉及多步电子-质子转移,其产物组分较复杂(包括C1到C3的产物),并且反应过程伴随着析氢反应(HER)副反应发生.此外,不同电催化剂的使用以及实验操作条件均对CO_(2)RR影响较大,导致目前CO_(2)RR催化剂性能尚不够理想,因而难以获得实际应用.为进一步开发性能良好的电催化CO_(2)RR体系,以及认识实际反应过程中催化体系真正的活性位点,理解电催化剂表面结构演变机制至关重要.本文综述了CO_(2)RR条件下非均相催化界面的动态演变行为.首先,本文讨论了催化界面动态演变的原理和分类.催化剂结构在实时工况下会发生演变,导致活性位点难以确定,因此需要明确催化界面动态演变的机制.动态演变行为主要分为催化剂表面形态演变和性质演变:表面形态演变主要指原子重排或迁移,该过程由热力学和动力学驱动;性质演变主要是化学态发生改变,它是催化剂表面性质和外界环境共同作用的结果.目前,大多数的研究都围绕着催化剂表面和次表面活性位点展开,所讨论的影响催化剂性质的因素主要包括化学组成、晶面和表面形态等.除催化剂内在性质外,还详细讨论了影响动态演变的外界环境因素,包括外加电位、温度、电解质以及杂质等.外加电位是影响催化界面的主要因素,电解质中的阴阳离子也对反应选择性有较大的影响.为了更好地认识反应过程中催化剂表面的活性位点,总结了光谱表征、X射线表征、微观表征等技术在研究催化界面动态演变行为中的应用.特别地,脉冲CO_(2)电解技术可以调节催化界面的动态演变行为,进而更好地调控反应的活性和选择性.在此基础上,理论模拟方法如密度泛函从头算和机器学习等方法,可以模拟环境条件驱动下的催化剂表面重构,为动态演变机制提供新的认识.本文还总结了当前研究电催化还原CO_(2)反应界面的动态演变行为所面临的问题和挑战,并展望了CO_(2)RR未来的研究方向.

Self-assembly multifunctional DNA tetrahedron for efficient elimination of antibiotic-resistant bacteria

Antibiotic resistance is a major challenge in the clinical treatment of bacterial infectious diseases.Herein,we constructed a multifunctional DNA nanoplatform as a versatile carrier for bacteria-specific delivery of clinical antibiotic ciprofloxacin(CIP)and classic nanoantibiotic silver nanoparticles(AgNP).In our rational design,CIP was efficiently loaded in the self-assembly double-bundle DNA tetrahedron through intercalation with DNA duplex,and single-strand DNA-modified AgNP was embedded in the cavity of the DNA tetrahedron through hybridization.With the site-specific assembly of targeting aptamer in the well-defined DNA tetrahedron,the bacteria-specific dual-antibiotic delivery system exhibited excellent combined bactericidal properties.With enhanced antibiotic accumulation through breaking the out membrane of bacteria,the antibiotic delivery system effectively inhibited biofilm formation and promoted the healing of infected wounds in vivo.This DNAbased antibiotic delivery system provides a promising strategy for the treatment of antibiotic-resistant infections.

Li-MOF-based ions regulator enabling fast-charging and dendrite-free lithium metal anode

Li metal has been regarded as the holy grail for the next-generation Li-ion battery.Li dendrites issues,however,impede its practical application.In general,prolonging the sand time of Li nucleation and regulating homogeneous Li^(+) flux are effective approaches to suppress the dendrites formation and growth.Regarding this view,a functional polypropylene (PP) separator is developed to regulate ion transportation via a newly designed Li-based metal-organic framework (Li-MOF) coating.The Li-MOF crystallizes in the orthorhombic space group P212121 and features a double-walled three-dimensional (3D) structure with 1D channels.The well-defined intrinsic nanochannels of Li-MOF and the steric-hinerance effect both restrict free migration of anions,contributing to a high Li^(+) transference number of 0.65,which improve the Sand time of Li nucleation.Meanwhile,the Li-MOF coating with uniform porous structure promotes homogeneous Li^(+) flux at the surface of Li metal.Furthermore,the Li-MOF coating layer helps to build solid-electrolyte interphase (SEI) layer that comprises of inorganic Li F and Li_(3)N,which further prohibits the dendrites growth.Consequently,a highly stable Li plating/stripping cycling for over 1000 h is achieved.The functional separator also enables high-performance full lithium metal cells,the high-rate and long-stable cycling performance of Li Ni_(0.8)Mn_(0.1)Co_(0.1)(NMC811)-Li and Li Co O_(2)(LCO)-Li cells further demonstrate the feasibility of this concept.

Computational study of transition metal single-atom catalysts supported on nitrogenated carbon nanotubes for electrocatalytic nitrogen reduction

Developing efficient and stable catalysts for the electrocatalytic N_(2)reduction reaction(NRR)shows promise in nitrogen fixation.Here,we proposed active and stable single-atom catalysts(SACs)toward NRR,where transition metals are anchored on nitrogenated carbon nanotubes(NCNTs).Among the screened nine common transition metals(Ti,V,Cr,Mn,Fe,Mo,Ru,Rh,and Ag)on(4,4)NCNTs,we found Mo-NCNT possesses the most excellent NRR catalytic activity and selectivity with a low overpotential of 0.29 V.Then,the NRR performance of Mo-NCNT was further engineered by controlling the nanotube diameter,where the lowest overpotential is 0.18 V at a diameter of 9.6Å.In addition,we found a linear scaling relation between*NNH and*NH_(2)on the studied catalysts with the exception of(2,2)and(3,3)Mo-NCNTs,owing to their extremely unstable structures.We attribute the outstanding NRR performance of Mo-NCNT to the moderate adsorption of N_(2)due to the slightly low d-band center of Mo,and the charge donating and accepting capacity of NCNTs.This work has provided a deeper insight into designing highefficiency and stable NRR SACs supported by NCNTs.

Active plane modulation of Bi_(2)O_(3)nanosheets via Zn substitution for efficient electrocatalytic CO_(2)reduction to formic acid

Formic acid is considered one of the most economically viable products for electrocatalytic CO_(2)reduction reaction(CO_(2)RR).However,developing highly active and selective electrocatalysts for effective CO_(2)conversion remains a grand challenge.Herein,we report that structural modulation of the bismuth oxide nanosheet via Zn^(2+)cooperation has a profound positive effect on exposure of the active plane,thereby contributing to high electrocatalytic CO_(2)RR performance.The obtained Zn-Bi_(2)O_(3)catalyst demonstrates superior selectivity towards formate generation in a wide potential range;a high Faradaic efficiency of 95%and a desirable partial current density of around 20 mA·cm^(-2)are obtained at−0.9 V(vs.reversible hydrogen electrode(RHE)).As proposed by density functional theory calculations,Zn substitution is the most energetically feasible for forming and stabilizing the key OCHO*intermediate among the used metal ions.Moreover,the more negative adsorption energy of OCHO*and the relatively low energy barrier for the desorption of HCOOH*are responsible for the enhanced activity and selectivity.

Long and Covalently Conjugated Branched DNA Structures for in Situ Gelation in Vivo

DNA nanotechnology has been widely employed for biomedical applications.However,most DNA nanomaterials rely on noncovalent complementary base pairing of short single-stranded DNA oligonucleotides.Herein,we describe a general strategy to construct a long and covalently conjugated branched DNA structure for fast and in situ gelation in vivo.In our design,a short and covalently conjugated branched DNA structure can normally be employed as the DNA primer in the terminal deoxynucleotidyl transferase-dependent enzymatic polymerization system.After enzymatic extension,the DNA aptamer-modified branched DNA structures with the sequences of poly T or poly A can immediately coassemble for in situ encapsulation of the target protein and tumor cell.The fast and in situ gelation system can function in a murine model of local tumor recurrence for targeting residual tumor cells to achieve long-term drug release for efficient tumor inhibition in vivo.This rationally developed DNA self-assembly strategy provides a new avenue for the development of multifunctional DNA nanomaterials.

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However.

A bifunctional wood membrane modified by MoS_(2)/covalent organic framework heterojunctions for effective solar-driven water evaporation and contaminant degradation

Interfacial solar evaporation technology is considered one of the most promising strategies for alleviating the scarcity of freshwater resources.However,solar-driven evaporation technology cannot eliminate the pollutants in the residual wastewater.To solve this problem,we have prepared a two-in-one solar-driven evaporation/photocatalysis system by decorating MoS_(2)/covalent organic framework(COF)heterojunctions on wood(MoS_(2)/COF-wood).Thanks to the unique porous structure of wood,it provides a strong guarantee for water transport and vapor release during the evaporation process.The introduction of MoS_(2)and COFs can promote the breaking of hydrogen bonds between water molecules,which leads to a significant decrease in the enthalpy of evaporation,achieving a water evaporation rate as high as 2.17 kg m^(-2)h^(-1)under 1 sun irradiation.Meanwhile,the resulting MoS_(2)/COF-wood exhibits good salt resistance and reusability.In addition,the heterojunctions formed between COFs and MoS_(2)can effectively inhibit charge carrier complexation and improve the photocatalytic degradation ability of pollutants(over 99%).This study highlights the construction strategy of bifunctional wood-based materials for freshwater production and wastewater remediation.